Latest articles from Saskatchewan Perennial Society

Blister Beetles — handle with care!

Cedric Gillott

Saskatchewan has about 20 species of blister beetles (aka oil beetles), ranging in body length from a few millimetres to about 2.5 centimetres. They are often conspicuously coloured and can be found on a range of plants though many have a fondness for solanaceous crops and legumes, especially caragana and alfalfa. Conspicuous body colour is a typical feature of many creatures (other insect examples include ladybird beetles, monarch butterflies and box elder [maple] bugs) and shows would-be predators that the owner is distasteful and to be eaten ‘at your own risk’.

The beetles get their common names from their ability, if handled roughly, to exude an oily material, a process known as ‘reflex bleeding’, from limb joints and other body regions where their cuticle is thin. The material released is actually their blood which contains cantharidin, a nasty chemical that causes blistering of the skin. In mild cases, gentle washing with warm soapy water will provide relief; however, if blistering is more severe, medical advice should be sought.

Much worse, cantharidin is highly toxic and if ingested, even in quite small quantities, for example, by livestock, can cause severe illness and ultimately death. Though veterinarians in Saskatchewan and Alberta are not aware of cases in these provinces, in the USA there have been several reports of blister beetles causing horse deaths. The horses were fed hay containing alfalfa that had been crushed to accelerate drying, an action that had also squashed resident blister beetles, releasing cantharidin into the forage.

Adults generally emerge from their overwintering sites in May/June, living for several weeks, feeding and mating. Then, depending on the species, female beetles lay their eggs in the ground near a grasshopper egg bed or the entrance to the nest of a ground-dwelling solitary bee. A few species place their eggs in flowers. At this point, blister beetle development becomes particularly interesting (at least for entomologists!). Unlike the vast majority of insects whose juvenile stage is either a nymph (as in grasshoppers) or a larva (like caterpillars, maggots and other beetle grubs), blister beetle larvae undergo ‘hypermetamorphosis’, a reference to the fact that there are two distinct juvenile stages. From the eggs, hatch highly mobile, 6-legged creatures (the nymphal equivalent) called ‘triungulins’, a reference to the three claws at the tip of each leg that are used for digging or clinging on to the host bee. Depending on where their mother originally laid her eggs, the triungulins dig down into the soil till they find a grasshopper egg pod, or they wait at the bee’s nest entrance or in the flower for the host’s arrival. When a bee arrives, the triungulins climb onto her, to be transported to the nest housing the bee’s own eggs and larvae.

From this point, the triungulins simply snack on the host’s eggs, and at their first moult change their form to become plump, immobile grubs (i.e., the typical larval form). With the onset of cold fall weather, feeding stops and the grubs remain dormant till spring. Then, depending on the species, they may continue to feed for a short time or immediately pupate, enabling metamorphosis to the adult form to occur.

Though as noted earlier, blister beetles show a preference for plants in the potato and pea/bean families, they will feed readily on many other plants. This may account for the rarity with which they reach pest proportions either agriculturally or in gardens. Should your veggie patch be invaded by a large enough number of blister beetles to warrant control, wear gloves and simply drop (or knock off) the beetles into a pail of soapy water where they will soon drown.Cedric Gillott is a retired entomologist and professor emeritus in the Department of Biology at the University of Saskatchewan. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; Check our website ( or Facebook page ( for a list of upcoming gardening events.

Clematis: Them that climb and them that don’t

Sara Williams

Two types of clematis can be grown on the prairies – climbers and non-climbers. Most gardeners are familiar with the former. While some do very well here, others need a great deal of coddling, coupled with your most protected microclimate and yet still may not survive. They share equal space on garden centres benches. So how does one know if the plant you’re considering will be hardy? Read the Latin names on the plant tags!

The hybrids of Clematis alpina and Clematis macropetala are among the loveliest, hardiest and easiest to grow.  They vary from 2.6 to 4 m (8 to 12 ft), climb by means of twining leaf stalks, and bloom from late spring to early summer on the previous year’s growth. They need little pruning unless blocking a window or an arbor. They benefit from deep, organically enriched soil, a 10-cm (4-in.) layer of mulch at their base and deep watering (to a depth of 45 cm/18 in.) every two weeks. Bloom is greatest in full sun.

The alpine clematis (Clematis alpina), native to Europe and Asia, has bell-shaped flowers in white, pink or blue, with each leaf consisting of three groups of three leaflets. Generally 2 to 2.5 m (6 to 8 ft) high, among the varieties are ‘Ruby’ with deep pink flowers, ‘Willy’ with pale pink flowers with a darker edge, ‘Constance’ with almost red flowers and ‘Francis Rivis’ and ‘Pamela Jackman’ with blue flowers.

The large petaled clematis (Clematis macropetela), native to China, is taller, between 3.6 and 4 m (10 to 12 ft), with bell-shaped flowers. Many have been developed by prairie plant breeders. Frank Skinner introduced ‘Blue Bird’ with lavender blue flowers, ‘Rosy O’Grady’ with long pink pointed sepals, and the snow white ‘White Swan’, while Stan Zubrowski’s ‘Joe Zary’ has double purple flowers.

Quite different from the above are hybrids of the herbaceous Clematis integrifolia and the climbing Clematis jackmanii. These begin growth each spring at ground level and climb to about 3 m (9 ft), blooming on the current season’s growth in late summer. The roots survive, but the foliage is killed to soil level each winter and should be pruned off in early spring. One of the best is ‘Blue Boy’, introduced by Frank Skinner in 1947. A more recent introduction from Latvia is ‘Pamjat Serdsta’ with light violet flowers.

Herbaceous, non-climbing clematis are less well known and not as readily available. They are in need of a marketing agent and a propagation push by wholesale growers. From 0.6 to 1.3 m (2 to 4 ft) high, they’re generally blue or purple, long-lived, hardy and well behaved. I’ve had some for more than thirty years and recommend them highly. Plant them in full sun or light shade in soil well amended with organic matter. Water them as you would most perennials. Remove the previous season’s dead foliage each spring.

The ground clematis (C. recta) is native to the hills and scrubland from southeast Europe to Russia. It’s 1 to 1.3 m (3 to 4 ft) high and covered with panicles of tiny 2.5-cm (1-in.), sweetly scented, star-shaped white flowers in mid-summer.

Mine conceals the lid of my septic tank.  Planted adjacent to what you wish to conceal, gently bend it over once it’s about 18 inches high, placing a small log on top to keep it there. It soon forms a mound of sweetly scented flowers – much sweeter than the contents of your average septic tank. To access the tank, simply move the mass of flowers and foliage to the side.

Purple ground clematis (C. recta ‘Purpurea’) is similar but with purple foliage. The purpling varies and is more pronounced on younger foliage.

The Hungarian clematis (C. integrifolia), native to southern Europe and Asia, including Hungary, is about 60 cm (2 ft) high with large, blue, nodding, bell- or urn-shaped flowers with white stamens.  It blooms from late spring to late summer, becoming somewhat sprawling as the season progresses, and benefits when supported by a peony hoop.

The hairy or fern-leafed clematis (C. hirsutissima), native to the Great Plains, has much divided, almost fern-like, foliage covered with long silky hairs. It’s similar in size and flower characteristics to C. integrifolia, but blooms in spring. The blue flowers are followed by feathery seed heads.  I obtained this in the mid-1970s from Bert Porter’s Honeywood Nursery and it’s been flourishing ever since. That’s fifty years!  A truly lovely and rare plant, I’ve never seen another source for it. If you find it, grab it!

Sara Williams is the author of many books including Gardening Naturally with Hugh Skinner, Creating the Prairie Xeriscape, and with Bob Bors, Growing Fruit in Northern Gardens. She gives workshops on a wide range of gardening topics throughout the prairies.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Upcoming event – Spring Plant and Seed Exchange and Plant Sale Tuesday May 30th 6:30pm at Saskatoon Forestry and Zoo Hall. Check our website ( for more details.

Spring has finally sprung

Erl Svendsen

Saskatchewan Perennial Society

Prairie springs are very short – the snow has only just melted, daytime temperatures are consistently above zero – and before you know it, trees are leafing out and the lawn needs mowing (but not quite yet). This spring sputtered once with the extra snowfall but I look at it as extra moisture, something that has been in short supply the last few years.  As I’m at the starting block waiting for Mother Nature to start the race into summer, now is the perfect time to start getting ready for the year ahead:

            •           Equipment maintenance: Get your lawn mower and rototiller tuned-up now to avoid the rush. While you’re at it, sharpen the mower blades. Sharp blades do less lawn damage, promoting healthy lush growth.

            •           Tools: Sharpen and clean your hand tools. Use an axe file to put a new edge on your shovels and hoes. For tools like pruners that require a finer edge, use a sharpening stone or replace the blade if it is damaged.

            •           Lawn care: Drain any standing water. Standing water that remains longer than a week or two is a problem not only for lawns but also trees and perennials. If you can, direct the water away from your yard with a ditch or pump it out to the street (but not your neighbour’s yard). Wait until early June (after the grass has started to grow) to dethatch or aerate.

            •           Tree and shrub care: Remove dead, damaged, rubbing or diseased wood. In the case of overgrown shrubs, remove up to one third of the oldest branches (thickest stems with darkest brown bark) at their base to rejuvenate. If you’ve had trouble in the past with aphids, leaf rollers, mites, or scale insects, consider applying a horticultural or dormant oil spray to trees and shrubs before they leaf out. Horticultural oil is a fairly benign product, that works by literally suffocating the eggs or overwintering insect stage rather than killing the adult insects with a toxic substance.

            •           Perennial care: Once your beds are somewhat dry, cut back perennials and remove dead and decaying leaves. You can put this organic material in the compost provided they weren’t diseased last year (e.g. don’t compost rust-infested hollyhock stems). Do this before new growth appears; ornamental grasses and chives are especially early to start growing.

            •           Mulch: Apply fresh compost or other organic mulch to preserve soil moisture and moderate soil temperatures around perennials, trees, shrubs and bush fruit during the growing season.

            •           Seeds: Order or purchase seeds for the upcoming season. Most vegetables can be started now (tomatoes, squash).

            •           Vegetable garden: As soon as the soil is dry enough, rototill your garden to loosen and warm up the soil. This will also bring overwintering pests and weed seeds to the surface to dry out or get picked off by our feathered friends. But remember: if you rototill when it is too wet, you will end up with compacted soil – and a muddy mess. Add organic matter such as well-rotted compost or manure. The common wisdom of waiting until the May-long weekend to seed or transplant seedlings applies to tender or chilling-sensitive plants such as beans, corn, cucumbers, peppers, potatoes, squash, tomatoes and the like. What you can plant now are beets, carrots, lettuce, peas, radishes and spinach for an early harvest.

            •           Enjoy: Relax and take a moment or five to admire the early flowering tulips, grape hyacinth, spring Adonis, pussy willow, liverwort (Hepatica) and forsythia. Or take a walk on the wild side (e.g. natural spaces) to catch a glimpse of prairie crocus (in Saskatoon, stroll through Prairie Crocus Park along the river bank, north of the city:

This should keep you busy, at home and off the streets for the next few weeks. Happy Spring!

Erl gardens in Saskatoon.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Upcoming event – Spring Plant and Seed Exchange and Plant Sale Tuesday May 30th 6:30pm at Saskatoon Forestry and Zoo Hall. Check our website ( for more details.

Plants for the pollinators

Candace Savage and Joanne Blythe,

Wild about Saskatoon

A quiet revolution is taking place in gardens all over Saskatoon. A renewal. A return to appreciating the beauty of the plants that have been blooming on these lands for thousands of years. By adding native plants to your garden, you can be part of this “growing” trend.

Why is it important to welcome native plants back into our neighbourhoods? We live in a time of crisis. The Earth is losing natural habitats at an alarming rate, and the prairies have been hit especially hard. In Saskatchewan as a whole, at least 80% of the grassland ecosystem has already been lost, either to agriculture and other industries or, increasingly, to urban sprawl. Around Saskatoon, the situation is even worse, with more than 95% of the natural vegetation gone.

Loss leads to loss, and it is unsurprising to learn that the populations of grassland birds are in free-fall, suffering the deepest and most widespread declines of any habitat group on the continent. Meanwhile, both regionally and globally, insects are suffering drastic slides in both diversity and abundance. Scientists have begun to warn of an “insect apocalypse.”

As the late, great biologist E. O. Wilson once noted, insects and other arthropods are “the little things that make the world go round.” Flowering plants, which provide the fruits and vegetables that make up the healthiest third of our diets, cannot survive without pollinating insects, notably bees. Birds cannot thrive without insect larvae to feed their young. Did you know that 95% of songbirds, including species that eat seeds as adults, require caterpillars to rear their nestlings? The plants nourish the insects; the insects nourish the birds. Everything is interrelated.

Meanwhile out in the garden, we can help to keep the circle of life turning by providing insects with the resources they need to thrive. Yes, we are talking about gardening for insects! That means growing native plants to sustain native insects. Supporting moths and butterflies through the stages of their complex lives involves choosing plants like goldenrods and sunflowers that feed lots of caterpillars, while at the same time making sure there are nectar-sweet blossoms like bergamot and giant hyssop to feed the flying adults. It means leaving leaf litter on the ground to protect overwintering eggs, pupae and adults.

And then there are the wild bees! We have at least 300 species of native bees in the province, some smaller than ants, others the size of your thumb. They need a variety of flowering plants that provide both nectar and protein-rich pollen as food for adults and young. Since different species have different preferences and needs, it is important to restore as much diversity and complexity to our native plantings as we can manage. Start small and watch how your interest and your garden grow.

Wild bees also need a shallow source of water and safe places to rear their young. Bumblebees might form a colony in a mulch pile or an old mouse nest. Most of our wild bees are solitary and nest in hollow stems or bare ground. Learn to enjoy a messy garden, and the bees will love you for it. Never, ever use insecticides or other poisons.

When you do all these things, gift after gift arrives–joy at that first hint of mauve as the crocus you planted last year emerges from the half-frozen ground, wonder at a sleeping bumblebee in a bergamot blossom, curiosity piqued when you spy a little red-and-gold bee land in fallen leaves. What could it possibly be called? As the plants take root and bloom in this place where they belong, we too begin to belong.

For more information, to view a gallery of native plants and find out how to register your own native-plant garden as a Pollinator Paradise, please visit us online at

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Growing potatoes on the Prairies

Jackie Bantle

Potatoes are one of the easiest and most rewarding vegetable crops to grow on the Prairies.  For each small seed tuber planted in the ground, a harvest of 5-10 tubers (depending on the cultivar) is typical.  No two potato cultivars are alike.  Every type of potato or cultivar has been bred for a particular purpose: boiling potatoes don’t necessarily fry well and baking potatoes don’t necessarily boil well. 

Potato cultivars recommended for boiling usually have interior flesh with a high water content and waxy texture:  these qualities ensure that they don’t turn ‘mushy’ during the boiling process.   ‘Norland’ and ‘Viking’ are red skinned, white fleshed, oval potatoes recommended for boiling.  Both cultivars are early maturing, however ‘Viking’ tends to produce larger and fewer tubers than ‘Norland’.  Both cultivars have moderate resistance to potato scab.  ‘Sangre’ is a dark red-skinned, white fleshed, oval potato recommended for boiling.  ‘Sangre’ matures slightly later in the season than ‘Norland or ‘Viking’ and is more susceptible to scab than Norland or Viking.  ‘AC Peregrine’ is a dark red-skinned, white fleshed oval potato recommended for boiling.  ‘AC Peregrine’ matures late in the season but it has an excellent tuber set.  Tubers do not tend to oversize. 

Two purple skinned, white fleshed potato cultivars that are recommended for boiling are: ‘Purple Viking’ and ‘Caribe’.  ‘Purple Viking’ is slightly later maturing than ‘Viking’ or ‘Norland’ and tubers tend to oversize.  ‘Caribe’ is similar to ‘Purple Viking’ except that the tubers tend to be more flattened in shape than ‘Purple Viking’.  Caribe is also more sensitive to common scab than ‘Purple Viking’. 

Several white/yellow skinned and yellow fleshed potato cultivars that are recommended for boiling include ‘Bintje’ and ‘Yukon Gold’.  ‘Bintje’ is a small-medium sized, oval potato with excellent flavour.  ‘Yukon Gold’ tubers mature earlier and are larger than ‘Bintje’,  however ‘Yukon Gold’ is more susceptible to potato scab than ‘Bintje’.  Both cultivars are also recommended for baking and frying.  ‘Shepody’ is an excellent, white-skinned, all-purpose potato (boiling, frying or baking) that matures early in season.  If left in the garden until the end of the season, tubers can become quite large and sometimes have hollow centres. 

One of the best tasting white/yellow skinned potatoes with yellow flesh is ‘Milva’.  This potato has excellent yields, matures in mid-late season and is excellent for boiling.  ‘Milva’ potato seed can be difficult to source.

Potato cultivars that are recommended for baking have a higher level of solids in their flesh, resulting in a firm dry texture after baking.  Potatoes with russet skins are usually recommended for baking.  ‘Russet Burbank’, ‘Russet Norkotah’, ‘Goldrush’, ‘Ranger Russet’ and ‘Umatilla Russet’ are all off-white fleshed, oblong potatoes recommended for baking and French frying. Of these five cultivars, ‘Russet Norkotah’ has the most uniform sized tubers however, the taste is probably the least favorable.  ‘Russet Burbank’ is the latest maturing.  If growing conditions are not ideal, ‘Russet Burbank’ tends to produce knobby and hollow tubers.  All russet potato cultivars are fairly resistant to scab infection. 

Potato cultivars recommended for frying or chipping have a high percentage of solids in their flesh and low sugar content.   The high solid content ensures the potatoes will stay crisp after frying while the low sugar content prevents the potatoes from becoming too dark when fried.  ‘Kennebec’ is a later maturing cultivar that is recommended for frying but also performs well when boiled or baked.  ‘Kennebec’ is moderately susceptible to scab infections.

Many gardeners try to get an early start by planting their potato tubers outdoors early in May. This is not recommended as the soil can be quite cool at that time of the year.  Cool soil conditions encourage potato seed tuber rot and a disease on potatoes known as rhizoctonia.  Rhizoctonia looks like specs of dirt on the potato skin but this so-called ‘dirt’ doesn’t wash off.  This fungal disease, Rhizoctonia solani, can reduce yields and even kill plants, if the infection is severe enough.

Avoid rhizoctonia infection by planting clean seed and planting into warm soil (at least 15°C).  An alternative to early spring planting is GREENSPROUTING your potato tubers.  Place your potato seed tubers under bright light conditions at room temperature about 3 weeks prior to planting out. Short, green sprouts will form on the potato tubers.  Once soil has warmed up, plant potato tubers in the ground as you normally would: take care not to break off the developing sprouts. By planting these pre-sprouted potato seed tubers into warm soil (3rd – 4th week in May),  plants will emerge quickly and disease incidence will be minimized. 

Jackie Bantle is a horticulturist working in the Dept. Of Plant Sciences, University of Saskatchewan. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Upcoming event – Spring Plant and Seed Exchange and Plant Sale Tuesday May 30th 6:30pm at Saskatoon Forestry and Zoo Hall. Check our website ( for more detail.

Spring Flowering Perennials (part 3 of 3)

Sara Williams

Saskatchewan Perennial Society

We’ll conclude our series on spring flowering perennials with globeflower, corydalis and hepatica. Last, but not least! And no spring garden should be without them.

Globeflower (Trollius spp.)

Trollius is one of the very few botanical names that is not based on Latin or Greek. It is from the Swiss-German trollblume, and, like the common English name, means a round flower. Native to the mountain meadows of Europe and Asia, they are hardy, trouble-free, and long-lived, forming slowly increasing clumps.

Varying in height from 30 to 80 cm (12-32 in.), they form neat, erect clumps of dark green, lobed or divided foliage. The globe-shaped or buttercup-like flowers are single or double. Their colour ranges from bright orange to almost white. They are fibrous-rooted.

Globeflowers require well-drained but evenly moist soil to which generous amounts of organic matter has been added. They grow best in full sun but will also do well in partial shade. They do struggle in heat or drought.

Place them in a perennial border or a waterside or bog garden. They are easily increased through division just after flowering.

Common or European globeflower(T. europaeus), native to the moist meadows of Europe and Britain, has lemon to buttery-yellow flowers and dark green, palmately divided, deeply toothed foliage. The plants range from 30 to 70 cm (12-28 in.) in height.

Trollius x cultorum hybrids generally have a globe-form flowers with their sepals rolled in, larger flowers, and good foliage. Among the varieties are: ‘Alabaster’, ‘Cheddar’,  ‘Earliest of All’ , ‘Lemon Queen’,  ‘New Moon’,  ‘Orange Princess’ and ‘Superbus’.

Ledebour trollius (T. ledebourii), native to Siberia, Korea and Mongolia, is usually available as ‘Golden Queen’ with deep orange, bowl-shaped flowers on plants 45 to 60 cm (18-24 in.) in height.

Dwarf globeflower (T. pumila), native to the Himalayan Mountains of northern India and China, forms small clumps of about 25 cm (10 in.) in height, with clear yellow, single flowers that open flat.

Noble fumitory, noble corydalis (Corydalis nobilis)

Here is a lovely perennial, one of the earliest to bloom, which should have a place in every northern garden. Sadly, it is seldom seen in our gardens. The blue-flowered corydalis are more readily available, but are not reliably hardy in most northern regions.

Photo by Sara Williams. Corydalis do well in full sun to partial shade in well-drained soil with even moisture.

First introduced to Europe in 1783, the noble corydalis is native to central Asia and Siberia. It forms leafy mounds of attractive, ferny, pinnately compound foliage with a blue-green cast. The flowers, in large dense racemes, are bright yellow with a brown tip, each with four petals, one of which is spurred. They appear in early spring on 45 to 60 cm (18-24 in.) stems. By early summer corydalis has entered dormancy, leaving not a trace until it emerges the following spring.

They do well in full sun to partial shade in well-drained soil with even moisture. Mark their position and take care not to place another plant over them once they become dormant.

This is a good border plant to place adjacent to a perennial that will modestly spread into the space vacated by the corydalis by midsummer. They are also well suited to the edge of a woodland or a shade garden. They self-seed in a very gentle and limited way.

Liverwort, liverleaf (Hepatica spp.)

Gardeners may complain about Latin names, but given a choice, there is no doubt that I would name a daughter Hepatica rather than Liverleaf or Liverwort. All of these names describe the leaves, said to resemble a human liver. The Greek word hepar means liver, while wort means a cure for. Both are based on the early medieval “Doctrine of Signatures,” wherein the signature or characteristic of a plant indicated its medicinal use as a cure. Thus, Hepatica was said to cure ailments of the liver. Hepaticas are lovely, hardy, and long-lived perennial that should be seen much more often in our northern gardens.

Place them in semi- to full shade in humus-rich but well-drained soil with a pH above neutral. Provide them with even moisture. Hepatica self-seed gently or can be divided. They are ideal for a shaded rock garden or a woodland garden.

Hepatica nobilis, 10 to 15 cm (4-6 in.) in height, is native to the subalpine deciduous forests of Europe and western Asia. The solitary, blue, pink, red, or white flowers appear above the previous season’s foliage in early spring. There are also double forms. The almost evergreen, dark green, basal leaves are three-lobed and develop after the flowers; they remain attractive throughout the growing season. The following are similar to the species except in flower colour: ‘Alba’ is white, ‘Rubra’ red, and ‘Rosea’ pink.

Transylvanian hepatica (H. transsilvanica) is very similar but is a more robust and spreading plant, and larger in all of its parts (15 cm/6 in. in height) than the noble liverleaf. Its azure blue flowers appear about a week later than H. nobilis. Its leaves are scalloped and pubescent.

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Spring flowering perennials (Part 2 of 3)

Sara Williams

Saskatchewan Perennial Society

If you want early spring bloom and you garden in the shade, three species of primroses (Primula) and five species of Solomon’s seal (Polygonatum) have proven rock hardy on the Canadian prairies. Try them!

Primroses (Primula spp.)

It’s hard to imagine a prairie spring without primroses. There are over four hundred species but only a handful flourish in our northern gardens. The genus name is from the Latin primus, meaning first, referring to its early spring flowers. All primroses do best in shade in evenly moist but well-drained soil well amended with organic matter. Among the hardy and long-lived species that have graced prairie gardens for years are Primula auricula, P. cortusoides and P. veris.

The dusty miller primrose (P. auricula) gets its common name from the white farina or flour-like substance that is found on its foliage that looks like the apron of a miller. Auricula means resembling an ear; the leaves were said to resemble a bear’s ear.

Native to the Carpathian Mountains and Austrian Alps, auricula primroses reached their peak of popularity in England during the Queen Victoria’s reign. They were the prima donna of parlour or conservatory plants, hundreds of new varieties were developed, and they were exhibited at shows with keen competition.

About 30 cm (1 ft) in height, the foliage is formed in a rosette of thick, grey-green, evergreen, basal leaves that are rounded to oval, with or without farina. The species has yellow flowers, but the colour range has been expanded to include blue, purple, pink, red, wine, and salmon, often with a contrasting white or yellow central “eye.”

Although one of the most sun-tolerant of the primroses, they are best suited to a shade garden, stream-side plantings or a shaded portion of a rock garden. Divide them in spring immediately after flowering.

The Siberian or cortusa primrose (P. cortusoides) has delicate umbels of pink flowers on stems of 15 to 25 cm (6-10 in.). The crinkled, light green foliage lends it a delicate appearance, but it is hardy and long-lived. Native to the forests of the Ural and Altai mountains, it has been cultivated in England since 1794.  It can be propagated by careful division. It also self-seeds (but with restraint).

The English cowslip(P. veris) is native to the meadows of Europe, including England, as well as those of Asia. Veris means of spring, when it blooms. The common name is more earthy and reflects the fact that it was often found emerging from cow dung in meadows. Only 20 to 25 cm (8-10 in.) high, the upright stems of the species produce lemon yellow, nodding blooms in one-sided, many-flowered umbels. The oval to oblong leaves are light green.

Solomon’s seal (Polygonatum spp.)

Photo by Sara Williams. Solomon’s seal is about 90 cm high with flowers in groups of four.

The common name, derived from the circular sunken scars left on the rootstock after the leaf stalks die—is said to resemble the signet ring worn by King Solomon. An alternative explanation, offered by Gerard in his Herbal, suggests that the dried powdered roots sealed wounds and healed bruises. Polygonatum, is from the Greek polys, meaning many, and gony, meaning knee, describing the jointed rhizomes of the roots. Although sometimes slow to establish, these are long-lived, low-maintenance plants.

Ranging in height from 20 cm up to 2 m (8 in.-6 ft), with graceful, unbranched, arching stems,  the pendulous, one-sided, creamy -greenish flowers develop from the leaf nodes. Dark, blue-black berries follow.

They do best in shade in evenly moist soil well amended with organic matter. Place them in a shaded border or woodland garden. Increase by spring division after flowering, including at least one bud per division.

Small Solomon’s seal (P. biflorum) is native to eastern and central North America, 60 to 90 cm (24-36 in.) in height, with greenish-white flowers, usually in pairs.

Giant Solomon’s seal (P. biflorum var. commutatum) is also native to North America, including Manitoba. The tallest of our Solomon’s seals, the stems range from 60 cm (2 ft) to 2 m (over 6 ft) with large, greenish flowers.

Dwarf Solomon’s seal (P. humile), only 10 to 20 cm (4-8 in.) in height, produces solitary, greenish-white flowers and is excellent as a ground cover. It is native to Japan and Korea.

Garden Solomon’s seal (P. x hybridum) is about 90 cm (3 ft) high with flowers in groups of four.

Common Solomon’s seal (P. odoratum) is native to the deciduous woodlands of Europe and Asia. The pendulous, white flowers, greenish at their apex, are usually in groups of three to five  on distinctly angled, arching stems of about 60 cm (2 ft).

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Spring flowering perennials a bit off the beaten path [Part I]

Sara Williams

Saskatchewan Perennial Society

It’s right about now that we become impatient for spring. So here are some spring flowering perennials to seek out at your local nurseries. They’re a bit off the beaten path, but well worth the hunt. With Easter Sunday approaching, we’ll begin with the European pasque flower.

European pasque flower (Pulsatilla vulgaris)

Similar to our prairie crocus but much more adaptable to garden culture, the pasque flower is native to England, western France, the Swiss Alps and into Ukraine. Like the prairie crocus, it is sought out in alpine meadows and sunny moors by folks who need assurance that winter is indeed over. It is called pasque flower because it flowers at Easter, and its sap makes a green dye once used to colour Easter eggs. The genus is from the Latin word meaning to sway, as the flowers move in the wind. Vulgaris means common (as opposed to rare).

European pasque flowers are hardy and long-lived. The finely divided, grey-green foliage is described as lacy or ferny. The leaves and stems are 25 to 40 cm (10-15 in.) in height and covered in soft hairs. The solitary flowers are in shades of white, pink, mauve, purple, and red, blooming in early spring. They are larger and of more intense colours than those of the prairie crocus. Attractive silky seed heads follow.

Place them in full sun and well-drained soil. They are moderately drought tolerant once established. They resent root disturbance and do not transplant well. European pasque flowers are ideal for a rock garden or edging a border. They may be increased by ripe seed or by very careful division. Among the varieties are ‘Alba’ and ‘Rubra’.

Photo by Sara Williams. The European pasque flower is native to England, western France, the Swiss Alps and into Ukraine.

Bloodroot (Sanguinaria canadensis)

If ever a flower belonged among the “spring ephemerals,” a term used to describe woodland flowers that bloom before the trees leaf out, it is bloodroot. When it is in bud, grab a cup of tea, a comfortable garden chair, your camera and a book of poetry. You have about forty-eight hours in which to sit and enjoy it. The flowers close at night and the petals soon fall. But it is breathtakingly gorgeous, especially the double form, ‘Multiplex’.

Both the common and species names (Sanguinarius is the Latin word for blood) refer to the red root sap that has been used as a dye by Indigenous peoples from Manitoba to Nova Scotia.

The cup-shaped white flowers with orange-yellow stamens are 7 cm (3 in.) in diameter and held on stalks of about 10 cm (4 in.). The basal leaves are as lovely as the flowers. Heart- to kidney-shaped, lobed and 15 to 30 cm (6-12 in.) across, they emerge vertical before they unfold. By midsummer, the plants have become dormant and disappeared. ‘Multiplex’ is similar but with double flowers. It lacks stamens and is longer lasting.

Place bloodroot in a shaded, protected location. They do best in evenly moist but well-drained soil to which generous amounts of organic matter have been added. This is a wonderful plant for a shaded border or woodland garden. It spreads slowly by rhizomes and can be propagated by careful division or by seed sown outdoors in the fall as the seed requires a cold period to ensure germination.

Siberian avens (Geum borisii)

Here is a perennial that should be much more widely available: long-lived, hardy and with excellent foliage and flowers. Named by Wilhelm Schact, a German horticulturist who was head gardener of King Boris II of Bulgaria, Schact found it while plant-hunting and named it after his king. Geum is its classical Latin name.

It forms compact, neat basal clumps, 25 to 30 cm (10-12 in.) high, of dark green, trifoliate, compound leaves, each with a prominent terminal lobe with brilliant orange flowers in May and early June.

Place it in full sun to partial shade in average, well-drained soil. Once established, it is quite drought tolerant. It is well situated in a rock garden, toward the front of a perennial border, or in a “hot border.”

It ispropagated by division, cuttings or fresh seed.

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Why not grow Kohlrabi?

Jackie Bantle

If you have not had the opportunity to eat fresh kohlrabi, you are missing out.  Kohlrabi (Brassica oleracea) is a member of the brassica family.  Other members of the brassica family include: cabbage, broccoli, Brussels sprouts, kale, cauliflower, turnips and radishes.

Unlike these other cabbage family members, kohlrabi does not have many of the insect and disease issues that these other crops experience.  Brassica vegetables are one of the crops that are ideally suited for growing in a northern climate: they are classified as cool season vegetables.

Kohlrabi comes from the German word, ‘kohl’ meaning cabbage and ‘rabi’ meaning turnip.  The earliest record of growing kohlrabi is from northern Europe approximately 500 years ago.  Kohlrabi is sometimes referred to as ‘stem turnip’ since the main edible part is the above ground swollen stem.  Kohlrabi flesh is crisp and the flavour is sweeter than cabbage.  Plants are either light green or purple in color.  Interior flesh is white.

All young brassica seedlings can withstand a couple of degrees of frost.  For this reason, kohlrabi can be direct seeded as early as the beginning of May.  Plant seeds approximately 1cm deep and about 2.5cm apart.  Spacing between rows should be 30-45cm.  Seedlings should emerge within one week.

Flea beetles are one of the earliest pests of all brassica plants and kohlrabi is no exception.  Flea beetles are tiny black flies (approximately 2mm in length) that jump from plant to plant and feed on leaves, giving a shot-hole appearance to stems and leaves.  They are especially devastating to young seedlings by completely devouring tiny cotyledons and the first true leaves as they emerge.  If flea beetles are a problem, cover new seedlings with thin crop covers for protection.  Alternatively, kohlrabi can be transplanted:  4-6 week old kohlrabi transplants are much more resistant to flea beetle damage than tiny emerging seedlings.

To grow your own kohlrabi transplants, seed plants indoors approximately six weeks prior to transplanting out (April 1st for planting out around May 15th).  Sow seeds in a commercial soilless media containing peatmoss, perlite and vermiculite.  Soilless media provides a disease-free environment as well as excellent drainage to minimize root disease problems.  Use flats, pots or containers with bottom drainage holes.  At a soil or media temperature of 24°C, kohlrabi seeds will germinate in 5 or 6 days. 

Kohlrabi seedling transplants require a minimum of 14 hours of light each day.  Supplemental grow lights will probably be necessary to produce healthy, sturdy transplants.  To test if you have sufficient lighting: the shadow cast on a white piece of paper at midday by an object 10 cm above a white piece of paper should have a definite outline.  If there is no outline, light is inadequate and plants will stretch toward the light, becoming leggy.  Contact your local garden center for appropriate grow lights.  Place lights 30-45 cm above the seedlings for 12-14 hours during the day to provide adequate light.  Fertilize developing transplants two times/week using 20-20-20 soluble fertilizer.  Mix according to label directions.

A common fungal disease that can infect developing brassica transplants is ‘Damping off’.  Symptoms of ‘Damping off’ include water-soaked stems that become constricted at the soil level.  Plants wilt and eventually collapse.  To prevent damping off, provide adequate air movement and light, avoid overwatering and crowding in young seedlings and transplants. 

Kohlrabi transplants can be transplanted outdoors as soon as daytime temperatures reach15°C and night temperatures are not below -2°C for several nights in a row.  Harden off transplants prior to planting out by moving them outdoors into a sheltered, frost-free location at least 3 days prior to transplanting. 

Mature kohlrabi plants range in height from 25-40cm tall.  Kohlrabi is ready to harvest when the swollen above ground stem reaches at least 7-8cm (late July – early August).   Early in the harvest season, harvest alternate plants within the row to allow space for remaining roots to expand.  Trim off the leaves close to the stem.  The above ground stem is the edible portion of the plant.  The outer layer of the stem can be woody and tough.  Peel these tough layers to expose soft, delicious flesh.  Kohlrabi can be eaten raw or steamed.  Oversize kohlrabi (15cm or more in diameter) may tend to have a dry and woody texture. 

Kohlrabi cultivars recommended for northern growing include: ‘Kossak’ (very large stem but good texture), ‘Purple Vienna’, and ‘White Vienna’.

Jill Thomson is a retired Plant Pathologist who lives in Saskatoon, where she enjoys gardening with her family, including the dogs. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Enjoying the wild garden

When we bought our house in 1987 the front yard was a conventional lawn, with a small horse-shoe shaped flower bed and a large spruce tree. Since then more trees have been added – we planted an Amur maple, oak tree and apple tree; the large spruce was removed, and smaller spruce, a flowering cherry, a mountain ash and an ash tree volunteered to grow. Over the years we also planted a dog wood hedge, forsythia, nine barks, haskap bushes, dwarf lilac, mock orange, barberry and rhubarb. Perennials were also introduced, some of which only lasted a few years because of lack of sun, but now we seem to have reached an equilibrium, with baneberry, valerian, maltese cross, harebells, a few grasses, spirea, growing in the understorey cover of goutweed and ferns.

One reason why I enjoy our wild garden so much is that it is very low maintenance. I pull out noxious weeds such as thistles and creeping bellflower, and remove surrounding plants that are starting to crowd any special favourites, such as the lady’s slipper orchid, gentian and tulips. I prune back robust bushes, if their neighbours need more space, and water very occasionally in a long, dry spell. I like to take a wander through to check on the early spring plants, like cowslips, and later I enjoy the scent of the lilac and mock orange.

 There are many animals that share our wild yard. There are birds in the garden all year round, and we encourage their visits with feeders and nest boxes. Woodpeckers, nut hatches, chickadees, house sparrows and house finches are regular daily visitors. This year we also have seen a flicker, and 2 little juncos who stayed all winter. Soon the waxwings will be arriving to eat the mountain ash berries, and once the snow has melted the spring migrants will be scratching in the leaf mat of old goutweed.

 When the summer birds return, we specially watch to see which wren boxes will be used. One year the box that was clearly visible from our front window was inhabited, and it was very interesting to see how many twigs were taken into the box, and the contortions that were necessary to wrestle some of the more awkward twigs through the small hole.

As fall approaches the birds, and wasps, will find the apples, and we are careful as we pick them. There are always a few left high up, or on the ground, so we do share amicably. There are hidden haskaps, mountain ash berries, and of course we start to fill up the feeders as the weather gets colder. We are visited by the youngsters of chickadees, nuthatches and other birds. This year we definitely have at least one pair of downy woodpeckers and I hope we will see their youngsters in fall 2023.

During the winter we see the tracks of rabbits and small rodents, and one spring we saw a white rabbit hiding under the bushes –we think it was the Easter bunny! Sometimes the bushes have been pruned back (by rabbits), and our apple tree lost some of the trunk bark many years ago (mouse damage), but everything has managed to survive.

The flowering of the haskap bushes encourages early visits by bees, and the pollination has been excellent resulting in berries to be shared between humans and birds. One year I had not noticed the berries were ripe, until there was much activity in the bushes as the birds got there first.

The bees are always busy in the pink, flowering rose bush that is on the eastern edge of the yard. The predatory, white crab spiders lurk under the flowers, waiting for a meal. The smaller bees are targets for the spiders but the larger bees can forage unscathed. There are always a few roses right until freezing, to feed the bees, and we also have veronica plants that they love.

There used to be milkweed plants in the sunnier spots and one year there were 7 monarch butterfly caterpillars that completed their life cycle in our yard. That was very exciting, but unfortunately the plants died out and I haven’t seen monarchs in our garden since then.

We had an infestation of slugs one year, so many they were trapped daily and removed from the garden, but they have not been a problem since. The ants like to run around on the peonies, which are also susceptible to mildew after flowering. I cut off the infected seed heads and the plants survive to flower another year.

I really hadn’t thought about how many animals live, or pass through, our wild front yard until I started to plan this article. Now I appreciate more than ever the diversity of wildlife that shares our space, enabling us to enjoy the wonders of natural history in our garden.

Jill Thomson is a retired Plant Pathologist who lives in Saskatoon, where she enjoys gardening with her family, including the dogs. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Currants and Gooseberries (Part II)

Sara Williams

Saskatchewan Perennial Society

Gooseberries have the largest fruit of the Ribes grown on the prairies, generally about 2 cm in diameter, similar to the size of grapes.

* ‘Captivator’ is thornless with red, pear-shaped fruit of good flavour that is larger than other varieties and very sweet.

* ‘Hinnomaki Red’ has flavourful red fruit good for both fresh eating and processing. It is thorny and somewhat sprawling and not as productive as other varieties.

* ‘Pixwell’ has medium-sized, pale green fruit which becomes pink when ripe. Its long pedicels and relatively few thorns make picking easier. It is productive, hardy and a consistent producer.

* ‘Poorman’ has pear-shaped, dark wine-red berries with excellent flavour. It is resistant to grey mould and mildew.

Planting and Care

Plant all Ribes species in early spring, spacing them about 5 feet apart. They do better in clay soils with a high organic matter content. If you garden on sand, add lots of compost, well rotted manure and peat moss to increase your soil’s moisture-holding capacity.

Ribes prefer shade for part of the day. In full sun, ensure that they have consistent moisture. Golden currants are adapted to full sun. To conserve moisture and control weeds, mulch currants and gooseberries to a depth of four inches to about 1 m beyond their drip line.

Avoid tilling as their roots are very shallow. Because of their shallow root systems, they are best fertilized with a top dressing of very well composted manure in early spring before growth begins. Alternatively, apply a granular fertilizer at a level much less than generally recommended. Their shallow root systems quickly take up nutrients and are easily “burned” by nitrogen. Theycompete poorly with nearby plants that have aggressive root systems.

Prune them in early spring before growth begins. Branches 3 years or older have generally reached the end of their productive years. Begin pruning at the base, as close to soil level as possible. Remove the oldest, thickest branches. By “opening up” the interior to sunlight and air movement, insect and disease habitat is reduced while flower production is increased, resulting in a higher yield of larger, tastier and better quality fruit.

Never remove more than 25% of a shrub’s total volume. As well, avoid simply “shearing” the exterior of a shrub. The plant responds by developing multiple new stems at the point of every cut, in effect, creating a “hedge” at the end of every sheared point. Instead of allowing sunlight and air penetration to the interior, you have further blocked it.

Powdery mildew is the most common problem encountered with Ribes. Select a resistant variety and plant them at the recommended spacing. Pests include aphids, fruit flies and spider mites.


Currants and gooseberries are usually ready for harvest from late July to early August. When picked, the stems remain attached at one end and sometimes the pistil and the dried flower are on the other end. Rub these off before eating or processing. Golden currants and gooseberries are very tasty to eat fresh but because of all the extra rubbing needed for each berry, many people prefer to process them for juice.  Black and red currants contain hard seeds that make juicing them a good idea. Some people prefer to boil, mash and then process the fruit through a food mill to extract the juice.  The berries improve in sweetness and flavour if allowed to remain on the bushes for two or three weeks after ripening.

And don’t forget the ice cream, eh?

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Currants and Gooseberries (Part I)

Photo by Sara Williams.
Black Currants are the most widely grown type of currant.

by Sara Williams

Hardly anything beats the flavour of homemade black currant ice cream – unless it’s currant syrup, jelly, wine or port. Yet relatively few Canadian gardeners grow currants. Part of the reason was the prohibition of their growth in the United States, beginning in the late 1800s, when it was discovered that black currants were an alternate host for the fungus that causes white pine blister rust. In Canada, their growth was strongly discouraged. With the introduction of resistant varieties of both pines and currants, by the 1960s, most restrictions were lifted or no longer enforced. But the sixty-year ban left several generations of North Americans totally unfamiliar with the taste of currants.
There are over 150 species of Ribes, mostly native to Europe, Asia and North America. The most widely grown on the prairies are the black currant (R. nigrum), red and white currants (R. odoratum), the gooseberry (R. uvacrispa and R. grossilata) and the golden currant (R. aureum and R. odoratum).

Currants and gooseberries are long-lived, prickly shrubs with a height and spread of 1 to 1.5 m (3-5 ft.). Most are “well behaved” in that they stay put and do not sucker. Their roots are thin and very shallow. Most have small, inconspicuous, cream coloured flowers. The exception is the golden currant that has larger, bright yellow flowers with red centres and a sweet licorice-like fragrance. Its common name is based on the flower colour and not the fruit colour. Berries are commonly black, but some may be red or yellow.
For good yields, black currants require the presence of at least two compatible varieties. Other Ribes can be planted as single varieties. But different species of Ribes will not pollinate one another. All are insect pollinated, so avoid the use of broad-spectrum insecticides.

Black currants are the most widely grown. The berries are about 1 cm across with an intense flavour. Although seldom eaten fresh, they are excellent in juice, wine, liqueur, ice cream, jam, jelly, syrup and candy. Much of the breeding has been carried out in Scotland. Black currants are very hardy. When varieties from around the world were grown at the University of Saskatchewan, all of them proved hardy, including those from Scotland!

  • ‘Ben Connan’ has large, easy to pick berries on upright plants.
  • ‘Ben Nevis’, resistant to rust, also has large, firm berries.
  • ‘Ben Sarek’ has large, firm berries that ripen in mid-season. The bushes are very productive, only 1 m in height, and resistant to mildew and rust.
  • ‘Willoughby’, introduced by Bert Porter of Parkside, Sk., has very reliable fruit production and is highly resistant to mildew.
    Red and white currants are smaller than black currants and formed in long trusses. They are seldom eaten fresh but are good for processing.
  • ‘Red Lake’ is very productive with large red berries in long clusters on upright, vigorous plants. They are excellent in jellies, syrup and wine.
  • ‘White Pearl’ produces long clusters of pale yellow, translucent berries with a sweet, mild flavour. They can be eaten fresh or used in pies and jelly.
    Golden currants, also called clove, buffalo or Missouri currants, are sometimes sold as ornamentals. They have yellow flowers but black fruit. The berries are larger and milder than those of black currants and are often eaten fresh. The plants are larger than those of currants and will sucker if left untended. They are very drought tolerant once established. Their flavour is similar to that of black currants but milder and considered more enjoyable to eat fresh. No varieties are currently (pun!) available.
    Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

What is crawling on my houseplant?

If you have houseplants, it is inevitable that at some point, you will also have bugs on your houseplants. There are a few insects that are familiar among Prairie houseplants. Hopefully this article will help you identify those bugs and manage them.
Fungus gnats and shore flies are the most common houseplant insect. Often described as, ‘those tiny, black, annoying flying insects that tend to fly around your nose, your glass of water and even your food when guests are visiting!’ Fungus gnats are weak fliers whereas shoreflies have better aim – like miniature house flies. Fungus gnats and shore flies prefer moist, cool soil to lay and hatch their eggs. To prevent fungus gnats and shore flies, ensure that the soil surface dries out between waterings.
If you already have a fungus gnat or shore fly problem, dry out the soil surface. Drench the houseplant’s soil with Steinernema feltiae nematodes (available at your local garden center). These nematodes will destroy fungus gnat and shore fly larvae in the soil. Place yellow sticky cards in various locations among houseplants. The yellow color of the sticky cards attracts insects. When the insects land on the card, they are trapped by the sticky substance on the surface of the card. Not only do these cards help to trap insects, but they also help monitor the type and number of insects that may be flying amidst the houseplants.
Spider mites are also common among houseplants. This tiny mites (<1mm long) suck juices from a plant. Signs of spider mite infestations include tiny yellow spots on leaves, fragile webbing near the growing points, wilting leaves and eventually, plant death. Tiny spiders are sometimes visible in the webs or on the underside of the leaves. Spider mites prefer hot, dry conditions. Control spider mites by increasing humidity around the plant: misting the plant several times each day for at least seven consecutive days should disrupt the life cycle. Insecticidal soap sprayed on the mites can also be helpful.
Aphids are small (1-10mm) sap sucking insects varying in color from light green to red to brown or black and are usually found on the undersides of leaves. Signs of aphid infestation include plants that have poor vigour and/or have a sticky substance on their leaves (aphid feces or ‘honeydew’). Wash aphid infested plants with a daily blast of water to disrupt the aphid life cycle or treat the plants with insecticidal soap. The insecticidal soap must cover the aphid to be effective. Parasitic wasps like Aphidius colemani can be purchased as beneficial insects however, their success rate can be variable, depending on the environment around the plants and the type of aphid present.
Whiteflies are small (1-2mm long & 3mm wide) white insects, triangular in shape and usually found on leaf undersides. Plants of the Solonaceous family (tomatoes, pepper, eggplant) and poinsettias are especially prone to whitefly invasion. To control a whitefly infestation, lightly vacuum plants or use sticky cards to reduce whitefly numbers.
Thrips are tiny (1mm), slender, oblong shaped light brown insects that are poor fliers but fast movers. Signs of thrip damage include distorted growing points and small brown lesions on leaf surfaces. Thrips are difficult to identify in a plant. Place a white sheet of paper beneath the suspected plant and gently shake the leaves of the plant. Thrips will fall on to the surface of the white paper where they are easy to see. Thrips are difficult to control: lightly vacuum plants, use sticky cards to reduce thrip numbers and apply a soil drench of nematodes (Steinernema feltiae) to control their larvae.
Mealybugs and scale can become significant problems in well-established houseplants. Mealybugs are soft bodied, oval shaped insects up to 5mm long and are white to pinkish-white in colour and covered in a white waxy material. They are usually found in groups on stems or in the axils of leaves and produce honeydew which turns into a white sooty mold growth. Scale insects are 5-10mm long and light to dark brown in color. They are found on the stems or undersides of leaves and are covered with a hard, shield like cover over their soft body (like body armor). Both mealybugs and scale can be controlled using Hort oil or dormant oil sprayed directly on the insect. Multiple applications may be necessary.
Prevent insect infestations by keeping your houseplants healthy. Remove any dead or dying leaves. Always place any new plant additions in quarantine, far away from other houseplants, until you are sure they are bug-free.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Root rot of house plants

When you live in a climate that is winter for half the year it is not surprising that many of us like to have indoor plants that provide us with growing vegetation in our homes. Some of us even put these plants outside for the summer months, and bring them back inside as the climate becomes incompatible. One of the most important factors for keeping your plants healthy and happy indoors is to learn about their likes and dislikes for temperature, light, soil type and watering. It is also important to bring them into your house in as healthy a condition as possible.
Watering and soil conditions are both critical in keeping the root system of your house plant healthy. Most plants do not want to sit in waterlogged soil; some (like ferns) will tolerate wetter soils for longer periods, and enjoy high humidity. Others (such as cacti) prefer soils that drain quickly and dry out between watering. So it is important to find out the requirements of your different plants, and not to treat all in the same way; maybe separate them physically, which makes it easier to keep the conditions required by different types of plants in separate locations.
When the roots of a plant remain in damp soil they are more prone to attack by fungi and bacteria that can cause rot. These pathogens may be introduced in your soil or be imported on the plant roots. Rot usually occurs when conditions are better suited for the pathogens rather than the plant roots. A wise precaution, when acquiring a new plant, is to repot it in a container that has adequate drainage, using potting soil of the correct nature for the type of plant. As an extra precaution, you can sterilize your soil by baking in the oven in a covered container for at least 30 minutes at 180-200 °F prior to planting.
The symptoms of root rot include yellowing or blackening of leaves that eventually die and drop off, despite adequate watering. The presence of fungus gnats indicates the soil is staying too moist for long periods, and root rot may develop. Also if the soil and plant become smelly, root rot may be present.
If you suspect rot, carefully remove the plant in its clump of soil, place in a shallow bowl of water, and tease the roots apart. If the roots are dark, blackened, soft and squishy then they are likely rotted. Healthy roots are usually creamy white to tan in colour and are firm to the touch. Often only part of the root system is affected and it is possible to cut the damaged roots back to healthy tissue, using scissors or pruners dipped in disinfectant (1 part bleach to 3 parts water). Cut back the above ground foliage, to match the amount of root remaining, then repot the plant in a container that has been washed and rinsed in bleach solution. Use sterilized potting soil, and place in growing conditions suitable for the plant. Always water pots separately so they are not sharing water draining from other pots, as this prevents pathogens from moving between pots and plants.
Drainage is extremely important and many attractive pots have no drainage holes. Find a smaller plastic pot with drain holes that will fit inside the decorative pot, and either sit the inner pot on a bed of gravel or, better still, remove it when watering, replacing once any excess water has drained away.
Plants do not easily recover from root rot. It is worth spending time on finding out what conditions suit your plants, in particular the water regime, to avoid root rot altogether. However, even if the root system is damaged, it may be possible to root a cutting from a stem. For example, coleus, ivy and other plants will form healthy roots on stems that are placed in water for a few weeks – it is worth a try!
Jill Thomson is a retired Plant Pathologist who lives in Saskatoon, where she enjoys gardening with her children, grandchildren and the dogs. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Apples – from Kazakhstan to the Prairies

Sara Williams and Bob Bors

Saskatchewan Perennial Society

Apples (Malus pumila) have been part of our prairie landscape almost since the time of European settlement with early immigrants bringing seeds from Europe and Russia. Apples are descendants of M. sieversii, native to the Kazakhstan mountains and taken to Macedonia in 328 BCE by Alexander the Great. Prairie plant breeders have done an admirable job of breeding hardy, high quality apples for well over a century – trees hardy enough to survive prairie winters were crossed with better quality apples from eastern Canada and Minnesota. The University of Saskatchewan fruit breeding program, under Dr. Bob Bors, continues to introduce high quality apples hardy to -40°C.

Prairie apple trees generally live for 30+ years before declining; with proper care they can last much longer. Apples are self-incompatible: two varieties are needed for cross-pollination. Ornamental crab apples can also pollinate eating varieties. In city gardens, having a single apple tree is not a problem where another tree is usually within bee-flying distance (e.g. in your neighbour’s yard). But in rural areas, plant two different varieties. All apples tend to bloom at the same time and most bloom after danger of frost.

Apples are grafted onto hardy rootstock, generally Siberian crabapple stock. Trees are up to 20 feet in height and should be spaced 13 feet apart. Apple trees labeled as “dwarf” have been grafted onto dwarf rootstock, usually “Ottawa 3” in zone 2. The dwarf rootstock reduces the height of the trees to about 10 feet (3 m), making them easier to prune, thin and pick. No ladders needed! Dwarf rootstock does not affect the size of the fruit. And dwarf trees begin bearing at three years of age as opposed to five years for standard trees. Dwarf apple trees should be staked because the top portion tends to grow more vigorously than the rootstock can easily support. If unsupported, they may fall over or break off. Use a heavy-duty metal or wooden fence post.

Plant apple trees in well-drained soil in full sun. Water them regularly (1 inch per week during the growing season; more in sandy soil, less in clay), especially when they are young. Once established, they are fairly drought-tolerant but benefit from irrigation during hot dry periods.

Fertilize moderately in early spring with compost, well-rotted manure or alfalfa pellets. Reduce fertilizer if winterkill or fire blight occurs. Prune off infected branches. Young trees will grow much faster without grass competition so give them at least a 3-foot diameter circle of mulch.  Mulch with post peelings, weed-free straw, grass clipping, chipper debris or flax shives to retain moisture, add organic matter to the soil, moderate soil temperature and reduce weeds. 

Apple trees are known for “biennial bearing” – producing so much fruit in one year that they lack sufficient nutrients and sugars to create flower buds (and fruit) the following year. In abundant years, branches may crack and break under the heavy fruit load. This cycle can be avoided by pruning and fruit thinning. Apples are formed on short branches called spurs that can produce for a decade or more. A few weeks after flowering, hundreds of small, immature apples fall. Called “June drop”, this can also occur in early July. But further thinning may be required. Use the “One Hand Rule”: spread your fingers and thumb far apart. As you hold your hand up to a branch, allow only one apple to remain in that space. This general rule of thumb (pun intended) assumes an average sized-hand and an average-sized apple. Thinning early in the season results in substantially larger fruit.

Apples in Saskatchewan ripen from mid-August through October depending on the variety. They can tolerate light frosts (-4°C) due in part to their high sugar content. Many of the last to ripen have the longest refrigerator life. The firmer an apple, the longer its storage life.

To learn about apple varieties recommended for prairie gardens, go to the University of Saskatchewan sites:  and Sara Williams is the co-author, with Bob Bors, of Growing Fruit in Northern Gardens. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

African Violets are Blue … and white, and pink and …

With African violets (Saintpaulia ionontha), the first thing that catches your eye is their cluster of brightly coloured, slightly iridescent blooms that sit atop a tidy interwoven rosette of velvety green leaves. They are also one of the easiest houseplants to grow and to keep flowering, giving you years of beauty. No wonder they have been popular for over 100 years.

African violet seeds were first collected in 1892 by Baron Walter von Saint Paul-Illaire, in what was then German East Africa and today is Tanzania.  Named Saintpaulia in his honor, almost all our modern hybrids are derived from these seeds, representing only two species, Saintpaulia ionontha and S. confusa.  My friend, Sara Williams, saw the wild species in their native habitat while visiting the Amani Nature Reserve in the East Usambara Mountains of Tanzania. They were growing on a vertical granite wall with water dripping down it, in a habitat so dark it required a flash to photograph them. In their native habitat they require constant shade and humidity and are dependent on surface rather than soil moisture.  

Today’s domestic varieties are much different than their wild ancestors. The fleshy, ‘fuzzy’ leaves are round to slightly pointed; usually light to dark green but can be variegated white and green, sometimes with faint pink tones; and margins can be smooth or wavy. The leaves form on a short stem in a circular, overlapping pattern to form a low rosette. Single, semi-double or fully double slightly iridescent flowers emerge from the leaf axils of recent growth and can be white, pink, red, pale blue, deep purple, striped, multi-hued or even spotted – the latest colour break-through is yellow. African violets range in size from miniatures of less 3 inches (1.5 cm) in diameter to giants of 16 inches (40 cm) wide.

When taking care of them, consider their natural habitat in Tanzania – moist and shaded in a semi-tropical mountain environment. Bright, indirect light is best (north- or east-facing window) and avoid direct sun as this may lead to scorched leaves. They will also grow quite well under fluorescent lights with 12-hour days. They prefer average room temperature with high humidity (the latter a challenge in winter). Fertilize with a weak soluble fertilizer solution once a month or use slow-release fertilizer.

African violets do not mind being slightly root bound and rarely require repotting (choose instead to start new plants, see below). Miniatures will be fine in very small pots (1.5- to 2.0-inch / 3- to 5-cm pots), while standard plants grow well in 4-inch (10-cm) pots. The potting mixture should be light textured (to avoid water logging) and contain organic matter. Specialized African violet potting mix is available. The root zone should be kept evenly moist but not overly wet to avoid root rot. Water with room temperature water and avoid wetting the foliage as this may cause spotting. Snap spent flowers and older leaves close to the stem.

African violets are easily propagated from leaf cuttings. Choose leaves from the middle of the rosette – avoid older (outside) or very young (centre) leaves. Use a sharp knife to cut the petiole (leaf stem) close to the stem. If the petiole is overly long, you can shorten it to 1.5 to 2 inches (3-5 cm). Insert the petiole at a slight angle about 0.5 inches (1 cm) deep into moist potting mix. You can have up to four cuttings in a 4-inch (10-cm) pot. Cover the container with a clear plastic bag to maintain humidity; place in indirect light. Open the bag occasionally to let out excess humidity. Rooting should occur in 3-4 weeks (you can check with a slight tug), and after about 8 weeks, small plantlets should emerge from the soil from the base of the cutting. Once the little plantlets have 3 to 5 leaves, carefully uproot the whole cutting, separate the plantlets from their ‘mother’ and plant in their own pots.

Erl gardens in Saskatoon and nurtures a few houseplants to keep his inside landscape looking green. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Colour echoes

Sara Williams
Saskatchewan Perennial Society
When new to gardening, many of us begin by acquiring perennial plants from our mother’s garden, a friend or neighbour, a horticultural society or garden club plant exchange or a nursery. Generally, these plants will be hardy and survive our tough prairie winters.
Our initial object may be simply to fill the available space within a bed or border. While we will probably pay attention to a perennial’s height, we may not initially be as aware of its season of bloom or precise colour.
At first, we get to know our plants – their growth habit, where they thrive (or not) and other characteristics. But few of us decide on a colour scheme when staring out. However, sooner or later, we begin to pay attention to colour. We may decide on an overall colour scheme for one portion of a border or a bed, then add plants with only those colours that harmonize with it. One approach to introducing a colour scheme is to use a colour echo.
So, what is a colour echo? Broadly speaking, it’s a colour in one plant repeated in a nearby plant. The idea of colour echoes was popularized by Pamela Harper, an American garden writer, who wrote Colour Echoes in 1994. “Too much sameness is boring, too much diversity bewildering, and colour echoes…although united by similarities, also involve contrast… in colour, form or texture.” They are a means of creating unity, serenity, interest and charm within a garden.
In practice, the echo can consist of two tones (a colour to which black or white has been added) of the same colour. One of the colours in a bi-colour or multi-coloured flower or leaf may be repeated in adjacent foliage or flowers. Often, the colour of two adjacent plants is the same, but the form or texture of their flower or foliage is very different. The colour of foliage is as important flower colour, but we seldom give it the same attention. Colour echoes can be used in multi-coloured (polychromatic) borders without major changes to the existing plants. These possibilities increase considerably in a mixed border that includes annuals, biennials, vines and shrubs as well as perennials.
Occasionally, we may see a perennial quite a distance away that would be a perfect colour echo for another and move it closer. As Helen Dillon, an Irish garden writer, wrote, “If you come to colour late in your gardening life, you will do a lot of transplanting…”
Some examples of colour echoes:
• The dark purple falls of a two-toned bearded iris echo the colour of a purple clustered bellflower.
• Hosta foliage with a white margin and the white fruit of dogbane.
• Puschkinia flowers and those of Siberian squill.
• The yellow foliage of Veronica ‘Trehane’ with that of a yellow and green hosta.
• The yellow flowers of Trollius globe flower with the yellow margin of hosta foliage.
• A pink tulip and the pink of a bleeding heart present the same colour but a contrast of foliage.
Echoes can also come from the hardscape. The colour in your house, garage, shutters, fences, gates, garden furniture or even a bird house can be repeated in nearby flowers. Many of the pink flowers in Claude Monet’s famous garden in Giverny, France, were a colour echo of his pink house.
Most echoes are found in close proximity, next to each other or along a path within a few feet. But in more expansive landscapes they can be viewed across a distance such as larger groupings of Bergenia with tulips of the same hue in spring.
Combinations among foliage plants are more long-lasting through the growing season. There may be disappointment if two flowers in a planned colour echo fails to bloom at the same time in a particular year. It’s safer to pair a foliage colour with those of a flower. The foliage will be there whenever the flower opens.
Often, we simply develop a border and are pleasantly surprised when an unintentional but pleasing colour echo appears.

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Seedlings, Clones and A Little Plant Breeding

Jackie Bantle
Saskatchewan Perennial Society

Genetic diversity, cloning and seedlings are words that all have one thing in common: they are the result of reproduction. Sexual reproduction results in seedlings that increase the genetic diversity of a particular species whereas cloning is a result of asexual reproduction.

Cloning is not a new technique. The Inca people of Peru cloned potatoes in the 1400’s by taking the underground tubers that they harvested and replanting them for the next season. Most of the potatoes that we plant today are clones of a variety that was developed sometime during the last century. The Oxford Dictionary of Botany defines a clone as “a group of genetically identical cells or individuals, derived from a common ancestor by asexual….reproduction”. When you a Norland potato tuber, you know that at the end of the season, you know that you will be harvesting red skinned, white fleshed potatoes that have a good texture when they are boiled and turn dark brown in color if they are deep fried. Garlic cloves, lily and gladiola bulbs, Jerusalem artichoke tubers and strawberry runners are all examples of plants that are reproduced as clones. Each selected plant part, whether it is a tuber, runner or bulb, is capable of producing a new plant that is genetically identical to the original individual.

Seedlings are tiny plants that are grown from seeds. Seedlings are not clones. With the exception of self-pollinated plants, like peppers, most seeds are a result of combined genetics from two different parents. One parent’s genetics are carried in the pollen while the other half of the genetics of the seed are found in the ovary of the flower of another plant of the same species. When pollination occurs, the pollen fertilizes the ovary and a new set of genetics are produced in the form of a seed. Seed, and the resulting seedlings, are important as they increase genetic diversity and allow plants to evolve and adapt to changing environmental conditions. Cloned plants have a limited ability to adapt to changing environments.

In fruit production, seedlings and clones both play a vital part in the fruit breeding process. A fruit breeder will take pollen from the flower of one tree that has certain promising characteristics and place that pollen on the stigma in a flower of another fruit tree of the same species with different promising characteristics. The hope is that the best characteristics of each tree will combine in one of the seeds found in the apple fruit. These seeds will be planted out the following spring. In a seedling orchard, hundreds or thousands of seeds may be planted out in one year. For apples, it takes approximately seven or eight years to produce fruit. During this time, many seedlings will be eliminated due to poor winter hardiness or growth habit. Seedlings that remain will be judged on their fruit quality. Color, texture, flavour, storability as well as variability will be some of the basic qualities that will be tested. Finding a new apple variety is a long and arduous process. It is estimated that if an apple breeder finds 2 or 3 good apple varieties during his or her entire breeding career (40 years), he or she has been extremely successful.

This pollination and cross breeding process not only happens with fruit trees but it is used in finding new cultivars of all sorts of food and ornamental plants. Once a seedling with desirable traits has been identified, that seedling will be cloned via methods such as plant cuttings, budding and grafting or more high tech methods of cloning such as tissue culture. These clones are then studied at various locations under various environmental conditions to determine whether or not they are worthy of mass production. The named cultivars of plants, trees and shrubs that you purchase at your local garden centre are clones of a seedling that was deemed to have superior genetics.

Both seedlings and clones play a significant part in food production in the world. Whereas the bananas that are exported out of Latin America all come from a single clone, it is the evolving seed market of field crops and vegetables that enable farmers to feed an ever-growing global population with high yielding, nutritious food. Traditional methods of manual crossing to produce seeds have evolved into molecular genetics, DNA marking and gene recombination. Whether modern or traditional methods are used, plant breeding is a process that requires careful observation, organized record keeping and diligence.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

The Holly and The Ivy ….and The Mistletoes

Mistletoe has been used by many ancient cultures, and although the leaves and berries of some species are toxic the plant has also been used historically for curing a number of ailments, including arthritis and infertility. It was also associated with peace and love by the Romans, who hung it over doorways to protect the household.
It has become a part of Christmas celebrations worldwide since the 18th century, and nowadays couples are expected to kiss when standing under a bunch of mistletoe. This tradition has been popularized by the music of the 50’s – “I saw Mommy kissing Santa Claus, underneath the mistletoe last night….”, and by more recent songs. The tradition of kissing under the mistletoe became very popular with the servants in Victorian times. Apparently any man could kiss a woman who was standing under the mistletoe, and if she refused him she would suffer from bad luck. At one time a berry was removed for every kiss, until the branch was bare – and presumably the kissing stopped. This tradition is no longer popular, probably because bunches of mistletoe are usually quite small and expensive in countries where the European mistletoe does not grow, and often artificial plants are used, making the berries non-expendable.
Mistletoes are hemiparasitic plants that feed on other plants, so they do not need roots to grow in the soil, or green leaves that can photosynthesize. They produce specialized structures called haustoria that penetrate the host plants’ tissues to extract the water and nutrients necessary for their growth. However, they do have leaves capable of photosynthesis for part of their life cycle. A commonly known species of mistletoe, the European mistletoe (Viscum album), is native to Britain and much of Europe, and it is the mistletoe plant used in Christmas decorations. It is very noticeable in British apple orchards, particularly in wintertime, when the trees are leafless. The mistletoe consists of woody stems that bear smooth-edged, oval, yellowish evergreen leaves and waxy, white berries that are present on the branches in clusters of 2-6. Mistletoe berries contain seeds that are coated with a sticky jelly called viscin, and for many species the seeds are spread by birds. Different kinds of birds spread the berries of different species, and they may use different methods. The seeds may be ingested, then regurgitated from the crop. Seeds of other mistletoe species may pass through the digestive tract and are then dispersed in the bird droppings. The seeds may also stick to the bill of a feeding bird, and are then wiped off onto the bark of a different tree. When the seed germinates on the branch of a suitable host, it produces a hypocotyl (the stem of a germinating seedling) that grows towards the bark of the tree, and eventually penetrates the bark. This can take a year or more, and until the haustorium is formed inside the host and reaches the conductive tissue, the mistletoe has to rely on its own photosynthesis to survive and grow.
Other species of parasitic plants that grow in a similar fashion are also called mistletoe, and they are found in many parts of the world, including South America and Australia. There is even a species of mistletoe that occurs in Saskatchewan. Dwarf mistletoe (Arceuthobium pusillum) is parasitic on white spruce and other conifers. It has a fragile stem, and small, scale-like leaves. There are male and female flowers, found on separate plants, and although the mistletoe plant itself is inconspicuous it causes the host tree to form many branches around the infected area. These bushy growths are called “witches’ broom” and are very noticeable. I recall collecting specimens from infected coniferous trees south of Meadow Lake for plant pathology classes in the 1980’s, and they were easy to spot. Dwarf mistletoe is not a species that could be used as a Christmas decoration! It is now rare in the province and is only found in eastern Saskatchewan.
Very best wishes for a happy holiday season, I hope you have many festive plants to enjoy.
Jill Thomson is a plant disease specialist (retired) who enjoys gardening in Saskatoon with her family, including the dogs. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Poppies, Poppies everywhere

Ginnie Hartley
Saskatchewan Perennial Society

Almost everyone recognizes the red poppy that many people wear on their lapels on Remembrance Day.  And many people know that Lieutenant-Colonel John McCrae, who was a Canadian Medical Officer during the First World War, wrote the poem ‘In Flanders Fields’, which speaks of the poppies that bloomed there. However, records indicate that the significance of the poppy can be traced back to the Napoleonic Wars in the early 19th Century, over 110 years before being adopted in Canada. Records from that time indicate how thickly poppies grew over the graves of soldiers in Flanders, France during those wars. These poppies are of the species Papaver rhoeas, the red-flowered corn poppy, which often thrives in areas of disturbed soil.

John McCrae’s poem inspired Madame Anna Guerin of France to found a charity which created poppies made of fabric, to raise funds to help rebuild regions of France torn apart by the First World War. She presented her idea of using the poppy as a symbol of remembrance for fallen soldiers to the Great War Veterans’ Association, the precursor to The Royal Canadian Legion, and it was adopted in 1921.

Some people choose to wear white poppies as an alternative to the red poppy. It symbolises remembrance of all casualties of war, including civilian casualties. But white poppies have been criticised for detracting from the meaning and the funds of the red poppy. Animal Aid in Britain issues a purple poppy as a reminder that both humans and animals are victims of war. In 2018, another unique commemorative poppy, the Khadi poppy, was commissioned by the Royal British Legion to mark the Centenary of the end of the First World War. The red cloth poppy is identical to the usual Remembrance Day poppy, but it is made out of the traditional handwoven Gandhian cloth (Khadi) and honors the British Indian soldiers who fought in the World Wars.

In 2014 a sea of 888,246 ceramic red poppies were used to form a weeping wall of red at the Tower of London, UK. This art installation was made to mark the 100 years since the start of World War One, and for four years it was moved and installed on other cathedrals in Britain.

Of course, poppies have uses other than for remembrance of the fallen. Their beautiful colors (not only red) make them a popular addition to flower beds. Growing them can be as simple as planting seeds in average, or even poor soil in a sunny location.  Roots can also be divided, and this should be done in the fall.

Ancient Egyptian doctors would give poppy seeds to their patients to relieve pain. The Minoan civilization (~2700 – 1450 BC) grew poppies for their seeds and used a milk, opium and honey mixture to calm crying babies. The seeds contain small quantities of both morphine and codeine. Seeds that are harvested about twenty days after the flower has opened are non-narcotic because then the morphine is no longer present. Seed capsules of the opium poppy can be processed chemically to produce heroin for medicinal use and for the illegal drug trade.

Poppy seeds are also a rich source of thiamin, folate and several essential minerals including calcium, iron, magnesium, manganese, phosphorus and zinc. They are often used as a spice and decoration for baked goods. The seeds can also be ground and used as a filling for pastries. They also produce an oil which has no odor and a pleasant taste, and is less likely than other oils to become rancid. The oil can be used for cooking, and also as a skin moisturizer.

The petals contain a red dye which is used in some medicines and wines. The dried petals are occasionally used to give color to potpourri.

So when you pin on your Remembrance Day poppy, remember that it is not only a symbol of memory, sleep and death, but also is ubiquitous in the flower bed, the pharmacy and the kitchen.Ginnie Hartley is a retired Speech-Language Pathologist who loves gardening almost as much as she loves words. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Pumpkin Celebration

Jill Thomson
Saskatchewan Perennial Society

In Saskatchewan, October could well be known as the month of the pumpkin, because of the 2 celebrations that both use pumpkins. In early October, on the Thanksgiving holiday, many families celebrate by eating a special meal together, and pumpkin pie is often a favourite dessert.  On October 31, we celebrate Halloween, and pumpkins are on display, carved so that a light can be inserted into the hollow pumpkin, to illuminate the carved design.

Many grocery stores have large bins of pumpkins for sale, some of which are now supplied by local growers. There are also “pumpkin patches” where you can select and buy pumpkins that are either pre-picked, or you can go out into the field to select your own. I visited a patch a few weeks ago and it was a very happy place, with small children, and adults, enjoying being able to choose ”their own” pumpkin.

It is not difficult to grow your own pumpkins as long as there is room in your garden for a plant that likes to ramble, climbing any obstacles in its path. The seed can be sown directly into the soil once the soil temperature is at least 15°C. However, the plants do need at least 110 days to grow to maturity and it is better to start seeds indoors not more than 3 weeks before the danger of frost has passed. The young plants can then be transplanted. It is important to remember, however, that vine crops do not like to be transplanted so disturb the pumpkins roots as little as possible when transplanting.  Pumpkins like a fertile soil, so well-rotted compost or manure should be incorporated before planting, and plants should be watered well during the growing season. They also like a sunny location, and we plant ours beside a corn row, as they will grow through or along the row. They will also climb up a frame, or wire, but then you need to provide a sling, or other support, for the developing fruit.

Pumpkins can grow very large, and heavy, depending on the variety you choose. Some gardeners like to grow huge varieties, with competitions to see whose is the largest. The world record weight in 2021 was 1226.1kg. That would make a lot of pies! Some people have grown them big enough to act as boats when they are hollowed out, and in 2021 a man from Nebraska paddled 38 miles down the Missouri, in a 384 kg pumpkin, to challenge the previous record of 25.5 miles.

Typically, we grow mid-sized pumpkins that are large enough to be carved at Halloween, but can still be carried by a strong adult. This year our ‘Big Moon’ plants produced big pumpkins suitable for carving, and  ‘Spirit’ hybrid cultivar was good for pies. We do also cook the flesh of the carved pumpkins to feed to our dogs:  this is an excellent addition to their diet and helps bulk-up a meal for any dog on a diet.

The tradition of carving pumpkins is connected to the ancient Celtic festival of Samhain, which marked the end of summer and beginning of the New Year in ancient Britain and Ireland. On that day the souls of those who had died would pass to the Otherworld, and other souls might return to visit their homes. In Ireland, people began to carve turnips into frightening faces, to scare away a particularly bothersome soul called Stingy Jack. The Irish folk who immigrated to the USA began to carve faces into pumpkins, which were readily available, unlike turnips. As the trend is now to make Halloween less frightening, and more a fun time for children, the carvings are not intended to be scary but are rather a display of the skill of the carver! 

Pumpkin plants are native to North America, and have been farmed by indigenous people for over 9,000 years.  Pumpkins ripen in the fall and were used for feasts at that time. Early recipes mention roasting a hollowed pumpkin filled with milk, spices and honey, over an open fire. Native Americans gave settlers gifts of pumpkins and demonstrated how to cook them. It is likely that cooking pies using a sweet pumpkin filling would have been developed by settlers preparing Thanksgiving meals. There are many variations on the pie, my favourite is a pumpkin cheesecake.  It has been estimated that about 50 million pumpkin pies are consumed for Thanksgiving every year in the USA.

Enjoy pumpkins this month; admire their glowing orange colours, the scrumptious desserts produced for Thanksgiving, and the elaborate carvings on display at Halloween.

Jill Thomson is a plant disease specialist (retired) who enjoys gardening with her family in Saskatoon. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check out our website ( or Facebook page (

Brussels Sprouts – a superfood

Jackie Bantle
Saskatchewan Perennial Society

As cooler temperatures bring us indoors and in closer contact with other humans at the start of flu season, many of us are looking for superfoods to boost our immune systems.  You may be familiar with the antioxidants found in blueberries, haskap and cranberries but were you aware of the cancer-fighting glucosinolates and immunity boosting Vitamin C in Brussels sprouts?  Brussels sprouts are considered a cold-weather super food.

Believed to be a descendent of Mediterranean kale, Brussels sprouts have a been popular vegetable for centuries, first gaining significant popularity in 13th century Belgium.  Like other members of the Brassica family (which include cabbage, broccoli and cauliflower), Brussels sprouts prefer growing temperatures around 20-25˚C for optimal growth.  However, unlike other brassica vegetables, Brussels sprouts require a long season to mature and must be transplanted in spring. 

Young Brussels sprout transplants look like any other cabbage, cauliflower or broccoli plant however, during the season, Brussels sprouts grow into 50-100cm tall stalks (depending on the cultivar).  Each stalk may produce 15-20 or more sprouts.

Brussels sprouts transplants should be started indoors, in spring, 6-8 weeks prior to transplanting out.  Seeds will germinate in 5 or 6 days after planting.  Supplemental light will be necessary to produce healthy, sturdy transplants.  Brassica transplants can be transplanted outdoors as soon as daytime temperatures reach 15°C and night temperatures are above 0°C.  Harden off transplants prior to planting out by moving them outdoors into a sheltered, frost-free location at least 3 days prior to transplanting.  Young brassica transplants that have been hardened off can withstand a few degrees of frost.

Brussels sprouts prefer full sun, rich healthy soil and about 2.5cm of water/week during the growing season.  By mid-season, there should be some sign of tiny sprouts forming in the leaf axils along the stem.  In order to get the modified leafy buds (sprouts) along the main stem to develop and enlarge, the growing point of each plant should be removed during the 3rd week in August.  Simply break off the top 1cm of the plant.  Instead of continuing to add growth on the top, the plant will put its energy into developing the sprouts along the side of the stem.  By early October, the sprouts should be a good size for harvest.  For best flavour, harvest Brussels sprouts after a fall frost (or two) of -3°C.  The cold temperatures sweeten the sprouts.  Brussels sprouts can withstand several hard frosts of  -4/-5ºC as long as day time temperatures allow plants to thaw during the day. Sprouts should be harvested when they are bright green and before they turn yellow. 

Harvest Brussels sprouts by removing the side leaves and cutting the stalks off just above the soil.  Remove any diseased or yellowing sprout leaves.  Store stalks and sprouts in plastic bags in the fridge for up to one week or remove sprouts from stalks and store sprouts in plastic bags in a fridge.  Ideal conditions for fresh Brussels sprouts storage is 1ºC and 80% RH.

For long term storage, blanch Brussels sprouts in boiling water for 4 minutes.  Remove from boiling water and immediately place in an ice bath.  Remove sprouts from the ice bath, pat dry and freeze in sealed plastic bags or containers.  Frozen sprouts can be stored for up to ten months. 

When cooking after freezing, do not allow sprouts to thaw before cooking.  Place frozen sprouts in sauté pan or oven directly from the freezer.  Overcooking tends to produce a mushy texture and excessive sulphur flavour.  Brussels sprouts are loaded with vitamin C, A, potassium, calcium and fiber.  Unlike many vegetables, Brussels sprouts contain protein (100g contains 3.4g of protein). 

Growing brassica vegetables like Brussels sprouts in an area where a lot of canola or mustard is grown on a large scale can be a challenge.  The large acreages of these two field crops attract a wide variety of Brassica pests and diseases to the Prairies.  Flea beetles, cabbage loopers, root maggots and club root are all possible problems with growing Brussels sprouts.  Be prepared to use crop covers or contact your local garden center for pest and disease control solutions.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check out our website ( or Facebook page (

Mum’s the word

Sara Williams

Saskatchewan Perennial Society

Chrysanthemums (Chrysanthemum x morifolium) (also known simply as ‘mums’) bring colour to the autumn border, are great cut flowers and are attractive to butterflies. But they require special attention to overwinter and are not easy perennials to grow in prairie gardens. Cultivated in China for over 2,500 years, they were brought to North America in 1798. The genus name is from the Greek words chrysan and themum, meaning golden flower. 

They have a short, fibrous root system which forms a dense, woody crown from which emerge many stems. Flowers may be single and daisy-like but are more commonly double. Varieties developed for northern gardens begin to flower in August, triggered by shortening days


Plant them in full sun in well-drained but evenly moist soil rich in organic matter. A summer mulch helps to maintain even moisture and suppress weeds. Use a balanced fertilizer such as 20-20-20 or organic fertilizers such as alfalfa pellets, blood meal or bone meal to promote vigorous growth. Pinch the plants in early summer to encourage branching and more abundant flowering.

After the first severe killing frost in fall, cover them with 15 to 20 cm (6-8 in.) of organic mulch such as shredded leaves or clean straw to prevent soil heaving and drying due to freeze-thaw cycles and to protect the crowns from winter’s cold. Remove the heavy mulch as soon as spring temperatures rise above freezing and snow recedes. Divide every second year to keep the crowns vigorous and improve their chances of winter survival. Plants can be divided as soon as the soil warms in the spring or from cuttings taken in early spring.

The Chrysanthemum Conundrum

Experienced prairie gardeners report very limited success in overwintering mums in the garden as they seldom survive without significant interventions in zone 2 and 3. It might be easier to simply treat them as annuals.

Hugh Skinner grew and propagated the Morden series of mums for years in his nursery near Roblin, Manitoba. He started plants in the greenhouse in late winter from stock plants overwintered for one year in the garden. These plants had been grown with excellent drainage and shelterbelt protection. With the exception of ‘Morden Garnet,’ which died, the Morden mums generally survived only their first winter outdoors. The following fall, the large clumps would be dug, potted, and stored in a root cellar until brought into growth in the greenhouse to produce cuttings in late winter.

Plants left in the garden generally did not survive a second winter. The “secret,” beyond planting them in a protected, well-drained site, was to divide or start new plants every second year.  The experience of a veteran gardener in Saskatoon has paralleled that of Hugh in Manitoba.


‘Baby Tears’ – compact plant (30 cm / 12 in. x 40 cm / 15 in.), white pompom flowers tinged pink.

‘Holly’ – golden yellow, pompom flowers on compact plants (40 cm / 15 in.).

‘Prairie Lavender’ – shell pink with yellow centres (60 cm / 24 in.).

            •           The Firecracker series, from Jeffries Nurseries, breed by Rick Durand, are about 50 cm (20 in.) in height.    

‘Dream Weaver’ – soft mauve-pink

‘Firestorm’ – mauve-pink to scarlet-red with yellow centres

‘Power Surge’ – double red

‘Showbiz’ – pink-mauve, pompom

‘Stardust’ – dusty mauve, quill-like petals with yellow centers

‘Suncatcher’ – bright yellow, double

‘Tiger Tail’ – bright orange-yellow

            •           The Morden Series, Agriculture Canada Morden Research Station, 1960s -1970s are 40 to 50 cm (15-18 in.) in height and spread.

‘Morden Cameo’ – double, creamy white (40 cm / 15 in.).

‘Morden Canary’ – bright yellow (45 cm / 18 in.).

‘Morden Delight’ – double, bronze-red (45 cm / 18 in.).

‘Morden Fiesta’- bright purple, compact (40 cm / 15 in.).

‘Morden Gaiety’ – bright orange (40 cm / 15 in.).

Other Species

Korean chrysanthemums (C. x rubellum hybrids) are reliable and generally easier to grow in northern gardens than those described above. The single flowers surround yellow disc florets.

‘Clara Curtis’ – deep pink, single flowers with yellow centres (60 to 75 cm / 24-30 in.), has survived for many years in Hugh’s Manitoba garden and in Saskatoon gardens with minimal attention.

‘Mary Stoker’ is of similar stature with yellow flowers overlaid with light pink.

C. weyrichii, an alpine species native to Japan and Sakhalin Island, has large, single, white or pink flowers (25 to 40 cm / 10-15 in.). The most available variety, ‘White Bomb’, is being used by Canadian breeders to develop hardy mums in a variety of colours and forms.

Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Water Wisely: Saving Water [Part II]

Much of the water directed towards plants never reaches them. It is lost to evaporation, runoff or “non-target areas” such as driveways or patios. Evaporation losses are affected by temperature, relative humidity, wind, droplet size and water pressure. We can’t control temperature but wind can be decreased by shelterbelts, trees and shrubs and fencing.

Design: In conventional landscape design, we consider height, colour, texture and season of bloom, but seldom think of the water needs of plants. We often combine plants regardless of their drought tolerance and then water the entire bed to satisfy the needs of those plants that require the most water.

When designing or redesigning your landscape, group plants in “zones” according to their water needs: those with low water needs (such as yucca, lilac, shrub roses), moderate water needs (cranesbill geranium, basswood/linden, dogwood) and high water needs (birch, delphinium, hosta). Once their water needs are considered, arrange them according to design factors such as height, colour and season of bloom. Grouping plants into beds or borders based on their water needs and then watering them accordingly, makes irrigation more efficient. With an automated system, each landscape zone is scheduled as a single unit.

Mulching: A 10-cm (four-in.) layer of organic mulch (e.g. leaves, shredded post peelings, flax shives) spread on the soil surface between plants, conserves water and greatly reduces weeds. It also prevents water splash onto foliage, thus reducing soil borne diseases such as botrytis.

Bowl-shaped depressions: Forming bowl-shaped depressions with mini “dykes” around newly planted trees and shrubs directs water towards the plants’ roots rather than onto adjacent soil.

Timing: Evaporation losses can be reduced by irrigating when it is calm and cool, usually in the early morning. Plants dry quickly once the sun rises, reducing the risk of foliage diseases such as powdery mildew (which proliferate rapidly under humid conditions). It is also a nonpeak time for domestic water use, so municipal water facilities are less likely to be overtaxed.

Angles: A spray directed at a higher angle covers a greater area, but considerably more water is lost to evaporation and wind drift because the water is in the air longer and wind becomes stronger with increased height. The lower the “angle of trajectory,” the less wind drift and evaporation. Higher pressure usually breaks up the stream of water into smaller droplets which are more easily lost to evaporation and wind drift. The older oscillating type sprinklers are one of the worst for water waste.

Moisture sensors and rain shut-off devices: Rain sensors can over-ride prescheduled irrigation systems so they will not operate when there has been sufficient moisture due to rain. An automatic timer on a hose end sprinkler allows you to water a predetermined amount without fear of forgetting to turn off the tap if you’re away. When a predetermined amount of water accumulates in a collector cup, the system is shut off.

In the fall…

Discontinue watering in late September or early October, when the leaves of deciduous trees have begun to colour and drop. This is your signal that they’re beginning to harden off for winter in response to progressively shorter days and colder temperatures. Continuous watering or the application of fertilizer in late fall may slow the hardening off, leaving trees as well as other plants vulnerable to winterkill.

Once all of the leaves have fallen, give them several deep waterings prior to freeze-up. The objective is to allow them to harden off yet enter winter dormancy with ample water in their tissue and the surrounding soil. This reduces vulnerability to late winter and early spring desiccation.

Retired from the University of Saskatchewan, Sara’s most recent book is Growing Fruit in Northern Gardens with Bob Bors. She’s been hosting garden tours for over 20 years – to Great Britain, Ireland, Europe, Turkey and Iceland. Join her for a tour of French gardens this September [Contact Ruth at 1-888-778-2378,] This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.

Water wisely: Water, Plants and Soil [Part I]

Sara Williams
Saskatchewan Perennial Society

With an average annual precipitation of 30 to 50 cm (12–20 in.), and with about half falling as snow, most plants require some degree of irrigation on the Canadian prairies during the growing season. Our philosophy should be to satisfy the needs of our plants without wasting water.

Understanding the relationship between water, soil and plants helps. Water, whether from rainfall or irrigation, percolates into the soil from the surface, filling the pore spaces between the solid soil particles and forming a “wetting front” that moves downward through the soil.

Different soils absorb and hold water at different rates. The amount of water the soil is able to absorb is called its “water-holding capacity” and is directly related to the organic matter content of the soil and the soil texture. Sandy soils absorb water quickly but have a low water-holding capacity, so lose it quickly as well. The same volume of water moves further and more rapidly in sandy soil. Clay soils absorb water more slowly and are prone to runoff and puddling if water is applied faster than it can be absorbed. The more organic matter, such as compost, that is added to the soil, the greater its water-holding capacity.

Plants themselves require the same amount of water whether grown in a clay or sandy soil. But plants grown in a sandy soil will have to be watered more frequently to obtain the same volume of water. 2.5 cm (1 in.) of water will penetrate to a depth of about 30 cm (12 in.) in a sandy soil and to about 15 cm (6 in.) in a clay soil.

By weight, water makes up 80 to 90 percent of herbaceous annual and perennial plants and about 50 percent of trees and shrubs. Photosynthesis and nutrient transport depend on water. Soil nutrients are brought to the root, enter the root and are carried through the plant in water. It is the internal water pressure that causes cell walls to stretch and cells to grow. As each of the many thousand cells forming a plant enlarges slightly, we see the overall effect as plant growth. As plants increase in size and their root systems penetrate deeper into the soil, irrigation should be less frequent but for longer periods of time, so the water will reach the deeper roots.

How to water

Ideally, water should be applied to the soil, where it can be absorbed by plant roots, rather than to the foliage. When watering established plants, water deeply and thoroughly, to the depth of their root system and beyond to encourage deeper rooting. Roots will only grow where soil is moist. Frequent shallow watering confines roots to the upper level of the soil, leaving plants with a shallow root system prone to drying out between waterings. Greater root growth allows greater water uptake.

Be aware of competition from aggressive plants with extensive, fibrous root systems. The shallow, far-reaching roots of poplar, Manitoba maple, Siberian elm and spruce can rob moisture intended for a nearby lawn, vegetable garden or flower bed.

Remember the trees

Watering your lawn does not mean you have watered the trees in it. Newly planted trees and shrubs need regular watering from planting time to establishment – usually two or three growing seasons. Water (or check the soil to see if water is needed) twice a week during their first month and once a week for the remainder of that season. Through their second and third seasons, water deeply twice a month or as needed. Water mature trees at their “drip line” rather than at their trunk. This is the soil area below the furthest extent of the tree’s branches. Feeder roots – those which absorb water and nutrients – usually end just beyond the drip line and are within the upper 40 cm (16 in.) of soil. Set a soaker hose under the drip line and leave it on until the soil is moist to that depth.

Retired from the University of Saskatchewan, Sara’s most recent book is Growing Fruit in Northern Gardens with Bob Bors. She’s been hosting garden tours for over 20 years – to Great Britain, Ireland, Europe, Turkey and Iceland. Join her for a tour of French gardens this September [Contact Ruth at 1-888-778-2378,]

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

The rhubarb patch

When I was young, I was convinced that rhubarb grew wild on the Prairies. Every farm that I visited and every abandoned farmyard that I drove past seemed to have a giant rhubarb plant in it. Rhubarb, however, was introduced to the Prairies by early settlers and originally entered North America via Maine and Massachusetts. Its origins are in parts of China (Chinese Rhubarb) and Russia (Russian rhubarb); growing wild in the cold climate of Mongolia, the Himalayas and Siberia. Records show that rhubarb grew on the banks of the Volga river over 3000 years ago. At that time, it was not used in culinary dishes: only the root was used for medicinal purposes. Records from 2700 BC in China indicate that the Chinese rhubarb root (Rheum palmatum) was used extensively as a laxative but also known for curing fevers, preventing the plague, reducing inflammation and healing soldiers. Chinese rhubarb (also known as Turkey or Indian rhubarb) has a much stronger taste and medicinal properties that the rhubarb commonly found in the North American garden (Rheum rhaponticum). The rhubarb that is grown on the Prairies today is a hybrid that was developed in the nineteenth century: the roots have little or no medicinal value.
Rhubarb is one of the few perennial vegetables that survive our harsh Prairie winters. Since it is a perennial vegetable, it is best to plant it along the edge of the vegetable garden where the roots will not be disturbed by tillage or digging. Rhubarb grows best in full sun and rich soil.
Rhubarb seeds will germinate, however, the resulting seedlings can vary greatly in flavour, texture and leafstalk color. it is most efficient to grow rhubarb from disease-free root divisions: dividing roots of a desirable plant ensures that you clone the characteristics that you want. Although rhubarb doesn’t need much care once it is established, it requires a good start. Rhubarb prefers fertile, well-drained soil Dig a hole that is .45m – .6m square. If you are planting a bigger plant or root division, dig the hole to at least twice the size of the plant. Space rhubarb plants at least 1.5m apart. Mature rhubarb plants can be 1-1.75m wide with 2m high flower stalks. The top of the crown should be no more than 5-7 cm below the soil surface. Fill the hole with a mixture of soil and compost (or well rotted manure). Add ½ cup of 10-10-10 fertilizer mixed in with the compost/soil mixture. Pack the soil firmly around the roots and crown being careful not to damage the crown. Fill the hole with the soil/compost/manure/fertilizer mixture until it is level with the surrounding soil. Water in the newly planted rhubarb however, avoid overwatering rhubarb: this will encourage root rot. Spring is the preferred time to plant rhubarb, but planting can occur any time during the growing season.
Later in the season, rhubarb plants may produce flower stalks. On young rhubarb plants, these flower stalks should be cut off near the base. By cutting off flower stalks, the plant will focus all of its extra resources into the roots and leaves rather than using resources to produce seed. Mature rhubarb plants are not negatively affected by seed production.
Rhubarb has few disease or insect problems on the Prairies. Gardeners should be aware of red-leaf disease, however. As the name suggests, red leaf disease is characterized by red or yellow leaves on a rhubarb plant that is losing vigour. The plant will be reduced in size and the crown of the plant may be rotting with leaves eventually turning black or brown. There is no cure of this disease: infected plants should be removed from the garden immediately. Do not replant a new rhubarb plant in the infected area and do not put the infected plant in the compost.
Rhubarb on the Prairies is typically used in desserts, jams, jellies or sauces. Oxalic acid is what gives the rhubarb its tart flavor. Oxalic acid can be poisonous when ingested at high levels. Large amounts of oxalic acid in our body can result in poor calcium uptake and kidney stones. Rhubarb leaves and roots have high enough levels of oxalic acid to be poisonous. Ensure leaves at the top of the petiole and rootstalk at the base of the petiole are completely trimmed off before cooking. Cooking or steaming rhubarb petioles reduces the level of oxalic acid in the petiole. Petioles can safely be eaten raw in moderate amounts. The flower stalks on rhubarb can also be eaten. The flower stalks usually have the texture of cauliflower along with a strong, sour flavor.
Jackie Bantle is a horticulturist working in the Department of Plant Sciences at the University of Saskatchewan. This column is provided courtesy of the Saskatchewan Perennial Society. Check our website ( or Facebook page

Dwarf Sour Cherries: Enter ‘D’Artagnan’

Sara Williams
Saskatchewan Perennial Society
Also called pie cherries, these are most often used in cooking and processing. Traditionally, Canadians call them “sour” while Americans call them “tart.” regardless of the fact that many of the new ones are sweet enough to eat fresh. The shorter varieties bred at the University of Saskatchewan are referred to as dwarf sour cherries or bush sour cherries.
Sour cherries are believed to be descendants of natural hybrids between sweet cherries (Prunus avium) and Mongolian cherries (Prunus fruticosa). But P. cerasus and P. fruticosa easily interbreed so those two may be the same species.
‘D’Artagnan’ (along with ‘Cutie Pie’ and ‘Sweet Thing’) is one of the latest varieties from the University of Saskatchewan’s fruit breeding program – plants should be available within the next 12 months. Named after the fourth musketeer in Alexandre Dumas’ novel, it is closely related to most of the Romance cherries and has the same parentage as ‘Juliet’, ‘Valentine’, and ‘Crimson Passion’. Considered the best variety for homeowners who want a hedge of cherries, it suckers more readily than those in the Romance series. Because it is propagated on its own roots, the suckers will have the same high-quality fruit as the parent plant. Within a few years, it will fill in the row, forming a hedge of thin, flexible branches. And, it needs far less pruning than other varieties. Not until the plants are about 12 years old is there a need to thin out older branches. (Most of the other varieties need pruning when 7 years old.)
Tested for over 15 years, ‘D’Artagnan’ has had consistent production with superior hardiness to ‘Carmine Jewel’. It is shorter than most of the romance series, reaching only about 6 feet (180 cm) in height while other varieties eventually attain 8 or 9 feet (240-275 cm). The burgundy fruit tastes similarly to ‘Valentine’ and ‘Juliet’. Most years it ripens in early to mid-August.
To form a hedge, plant them about 3 feet (1 m) apart within a 3-foot (1-m) wide row. Mulch well to prevent grass or weed competition. Once suckers appear between the plants, allow them to fill in the rows.
Sour Cherry History 101
In the 1940s, Les Kerr (then superintendent of the PFRA Sutherland Tree Nursery) began hybridizing sour with Mongolian cherries with the goal of developing sour cherries hardy to zone 2. His job description limited his breeding to trees and shrubs useful in prairie shelterbelts. Chastised by his superiors for working with sour cherries, Les went underground. He continued his clandestine cherry breeding, giving his seedlings to various farmer friends for planting out. In 1983, while gravely ill and hospitalized, he met with Dr. Cecil Stushnoff, then head of the Horticulture Department. During that bedside meeting, Les revealed which farmers were maintaining his best seedlings. Les passed away a week later.
Dr. Stushnoff and technician Rick Sawatzky gathered Les’ best selections and relocated them to the University test plots. Les’ hybrids were a great improvement over the Mongolian cherries. By the late 1980s, Rick had begun crossing Les’ best selections with sour cherries from northern Europe with the goal of improving fruit size and flavour. He released ‘Carmine Jewel’ in 1999, just as Dr. Bob Bors became head of the fruit breeding program. Together, Rick and Bob began selecting the cherries that would eventually become the Romance series. These new cherries fulfill, and in some way surpass, Les’ original goal to develop sour cherries hardy to zone 2.
Retired from the University of Saskatchewan, Sara’s most recent book is Growing Fruit in Northern Gardens with Bob Bors. She’s been hosting garden tours for over 20 years – to Great Britain, Ireland, Europe, Turkey and Iceland. Join her for a tour of French gardens this September [Contact Ruth at 1-888-778-2378,]
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening event

How to prevent powdery mildew disease from taking over

Jill Thomson/Submitted
Powdery mildew infection of peony seed heads.

Jill Thomson
Saskatchewan Perennial Society
This growing season, there seem to be many plants affected by mildew early in the season, particularly in my shady front yard. The affected leaves are easily recognisable by the typical, white fungal growth, usually first noticed on the upper surface of infected leaves.
Powdery mildew is the common name for this fungal disease that attacks many different species of plants. Although the symptoms are usually very similar, there are very specific mildew fungi that cause disease on different hosts For example, mildew on grasses is caused by Blumeria (Erisyphe) graminis and on roses by Sphaerotheca (Podosphaera) pannosa. Lilacs are infected by Erisyphe syringae, whereas Sawadaea bicornis affects peonies. These mildew fungi have very similar life cycles: in the summer the fungus grows on living plant material and spreads from leaf to leaf, and from plant to plant by tiny airborne spores called conidia. These spores germinate on new plant surfaces and can penetrate the leaves, where they form specialized structures called haustoria. Haustoria have a central body with multiple finger-like projections that extract nutrients from the plant cell enabling the fungus to feed off the living plant.
Mildew is known as an obligate parasite because it must feed on living tissue. Mildew does not usually kill its host, but it will hasten the host’s decline. As the amount of infection increases, towards the end of the season, the fungus produces hard walled, black, pinhead-sized structures that can easily survive winter conditions. In the spring these structures produce a spore that initiates new infection, and once the infection is established, the summer spores are responsible for local spread of the disease.
In some plants, infected leaves can become misshapen: rose and high-bush cranberry leaves infected by mildew are curled and distorted as they expand. Peony flower heads seem to be more heavily infected after the petals begin to fall.
There are a number of ways to reduce mildew infection, and these apply to many types of garden plants – grasses, bushes, vegetables, annuals and perennials. Controlling the environment around your plants is a major tool to prevent or reduce mildew infection.
• Start by giving your plants space to allow good air circulation around and through the plants.
• Trim away bottom branches of lilac and rose bushes.
• Grow your plants in open, sunny areas, as long as these are also the right conditions for your plants.
• Although mildew spores do not need free water on the leaf surface in order to germinate and infect, they thrive in high humidity. To reduce infections, always water around the base of your plant in the morning, so the leaves can dry off quickly.
• Avoid using excessive nitrogen fertilizer as this encourages tender, new leafy growth, which is more easily infected than older, tougher growth.
• Remove infected material and clean up fallen leaves in the fall. This debris provides material for the overwintering stage of the fungus and will supply a new source of mildew infection in the spring.
• Mulching around bushes in the fall also keeps the spores from reaching leaves in the spring.
• There are some chemicals that can be purchased to help control mildew on favourite plants as well as many home-made recipes on gardening websites. Always treat a small area of the plant first, to see if it reacts adversely, allowing 24-48 hours to check for a response.
• When shopping for new plants, choose varieties that show resistance to mildew, if you are experiencing a persistent problem in your garden. There are roses that are less likely to develop mildew, however, they are not completely resistant.
These preventative measures also apply to the vegetable garden. Allow for good air circulation around your plants, in particular with cucumber, squash, pumpkins, muskmelon. These vine crops need to retain productive leaves to grow to maturity, so space them out to avoid early mildew infection. Young pea plants usually resist mildew infection; however, older plants almost always succumb to the disease, often after the main productive stage is over.
Mildew in your garden is something you cannot usually avoid, but keeping it to a manageable level is possible most years.
Jill Thomson is a plant disease specialist (retired) who enjoys gardening with her family in Saskatoon.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Hardy Clematis that flourish on the Prairies

Sara Williams
Saskatchewan Perennial Society
Clematis (from the Greek word for vine) are among our most beautiful vines. While many do very well on the Prairies with average care, others, such as the Jackmanii, need a great deal of coddling, coupled with your most protected micro-climate, and still may not survive our winters. On benches in garden centres and nurseries, they all share equal space. So how does one know if the plant you’re considering is ruggedly hardy or needs shelter? Begin with the Latin or botanical name – which should always be listed on the plant tag in italics.

The hybrids from Clematis alpina and Clematis macropetala (both native to China), are among the loveliest and toughest. They vary in height from 2.6 to 4 m (8 to 12 ft.) and climb by means of twinning leaf petioles, so allow space behind their supports for the leaves to do their job. Both species bloom on the previous year’s growth from late spring to early summer. The hybrid varieties of both species need little pruning unless they’re blocking a window or an arbor, usually every three or four years. They benefit from being planted in deep, organically enriched soil with a 10 cm (4 in.) layer of organic mulch at their base, and deep watering (to a depth of 45 cm/18 in.) every two weeks. Bloom is greater if the vine is in sunlight. These clematis are hardy, easy to grow and vigorous. No fuss, no muss.

The alpine clematis (Clematis alpina), native to the alpine slopes of Europe and Asia, was introduced to England in 1792. It has bell-shaped flowers in shades of white, pink or blue. Its compound leaves consist of three groups of three leaflets and twine around its support as it grows. They generally reach heights of 2 to 2.5 m (6 to 8 ft.). Among the cultivars are ‘Ruby’ with deep pink-dusty rosy red flowers; ‘Willy’ with pale mauve-pink flowers with a darker edge; ‘Constance’ with bright pink, almost red flowers; ‘Francis Rivis’ with larger deep blue flowers; ‘Pamela Jackman’ with rich, deep purple-blue flowers; and ‘Helsingborg’ with deep purple flowers.

The large-petaled clematis (Clematis macropetela) was first discovered in China by a French missionary, Pierre Nicholas Le Chéron D’Incarville, in 1742. But it was not introduced to Europe until just before World War I. It is slightly taller, generally between 3.6 and 4 m (10 to 12 ft.), with bell-shaped flowers. Many of its varieties have been developed by Prairie plant breeders such as Frank Skinner and Stan Zubrowski. Among the Skinner introductions are ‘Blue Bird’ with deep lavender blue flowers, ‘Rosy O’Grady’ with long dark pink pointed sepals, and the snow white ‘White Swan’. ‘Joe Zary’, honouring one of Saskatoon’s promoters of horticulture, has double purple flowers and was introduced by Stan Zubrowski of Prairie River. Other Clematis macropetala varieties include ‘Lagoon’ and ‘Maidwell Hall’ with blue flowers, and ‘Markham’s Pink’ with pink flowers. ‘Jan Lindmark’, a Scandinavian introduction, has dark bluish-pink flowers, while ‘Purple Spider’ has double purple flowers.

Quite different from all of the above are the hybrids of the herbaceous Clematis integrifolia and the climbing Clematis jackmanii. These begin growth each spring at ground level and climb to about 1-2 m (3-6 ft), blooming on the current season’s growth in late summer. Although the roots survive, the above-ground portion is killed to soil level each winter and must be pruned off in early spring. One of the best known of these is ‘Blue Boy’, introduced by Frank Skinner in 1947. A lovely blue, it blooms in late summer. A more recent introduction from Crimea, Ukraine is ‘Pamiat Serdta’ with light violet flowers.

Note: The golden clematis (Clematis tangutica) is listed on Alberta’s noxious weed list and is discouraged by the Native Plant Society of Saskatchewan because of its vigour and abundant self-seeding.

Retired from the University of Saskatchewan, Sara’s most recent book is Growing Fruit in Northern Gardens with Bob Bors. She’s been hosting garden tours for over 20 years – to Great Britain, Ireland, Europe, Turkey and Iceland. Join her for a tour of French gardens this September [Contact Ruth at 1-888-778-2378,]

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events

Don’t let slugs force you to sell your house!

Erl Svendsen
Saskatchewan Perennial Society

I joke that I sold my last house because I found myself sharing the garden with a multitude of slimy slugs. That wasn’t really the reason for moving… at least not the only one.

Slugs are gastropods, not insects. They are related to snails and clams rather than to flies or beetles. They should not be confused with pear slugs which are insects (the larval form of a sawfly), found on cotoneaster, pear, mountain ash and other related woody plants.

Slugs are nocturnal and the most telling clue that they are resident in your garden, aside from their damage, is the silvery trails they leave behind. Their preferred habitat is damp – which unfortunately describe a lot of territory.

Growing up on the West Coast where slugs come in many shapes, sizes and colours, I particularly remember the banana slug named for its resemblance to said fruit in colour AND size. Thankfully, in most Saskatchewan gardens, you’ll typically only encounter the diminutive grey garden slug (Deroceras reticulatum): small, 1-2 cm long, dark to light grey, shiny and, of course, slimy. Don’t let their size fool you. What they lack in size, they can rapidly make up in numbers, laying 200-300 eggs at a time. And in numbers, they are voracious, decimating leafy plants (e.g. hostas) and many other garden plants including root crops like potatoes and carrots (unfortunately not dandelions in my experience).

Selling your home is not a guaranteed or a long-term solution because slugs or their tiny eggs can move in from the neighbour’s yard, on plants from the nursery or your friends, on borrowed tools and even on the bottom of your shoes.

There are ways to fight back. Start by making your garden less hospitable by removing daytime hiding places such as wooden boards, bricks, stones, and garden gnomes. Remove all decaying vegetation throughout the season especially in the fall.

Trapping slugs is a good next option. They are attracted to yeasty, fermenting odors. But don’t waste your beer: add a package of bread yeast to a cup of water sweetened with sugar, stir and set aside to bubble away for a couple of hours. Add an inch of the yeast solution to any shallow container (e.g. empty cat-food or tuna tins). Place several in the garden in the early evening, about 10 feet apart. Next morning, empty the containers (hopefully filled with drowned slugs) and repeat. Another option is to place short boards in the garden. In the morning, just scrape any cowering slugs off the bottom-sides into a bucket of soapy water or straight into the garbage. Repeat. Another effective trap is an upside down rind of a half grapefruit. Slugs can’t help themselves and will be found munching away in the morning on the inside. Simply dispose of rind, slugs and all. Repeat.

There are a number of other control options, most of which are safe to use around the home, your children and pets. Slugs are said to avoid wood ash and coffee grounds (some coffee shops give bags of grounds away for free). If nothing else, the ash and grounds will help enrich your soil. To a slug, crushed baked eggs shells sprinkled around the garden act like razor wire, as does diatomaceous earth (DE), a powdery substance composed of sharp fossilized microscopic hard-shelled algae or diatoms. There are several registered insect and slug control products that are 100% DE (e.g. Safer’s Insectigone). Pool-grade DE is not effective in controlling slugs and other insects because it has been exposed to high heat during processing, altering it significantly. Wear a facemask to avoid breathing in the fine particles when sprinkling them around the garden. Reapply after heavy rains.

After a meal of eco-, human- and pet-friendly iron-based slug and snail killer, slugs stop feeding permanently and die (look for products containing sodium ferric or ferric phosphate). As a last resort, there are also registered metaldehyde-based slug control products. While very effective, metaldehyde is poisonous to slugs, people and pets alike and should be used with care.

Erl gardens in Saskatoon and enjoys being a climate zone denier by trying new and interesting perennials. This column is provided courtesy of the Saskatchewan Perennial Society (SPS; ). Check our website ( or Facebook page ( for a list of upcoming gardening events.