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, www.worldwideecotours.com]
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening event

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; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events

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, www.worldwideecotours.com]

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events

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; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.

Mugo pine (Pinus mugo) is native to the mountains of southern and eastern Europe, from Spain to the Balkans. The species name, mugo, is the old Tyrolese name for this pine. Tyrol is a region in the Austrian Alps to which it is native.

Mugo pines have been gown on the prairies for over a century. You can still see venerable specimens in older neighbourhoods. Some are as high as a two-story building. These hark back to an era when they were grown from seed and the seedlings could be extremely variable in size and height. Today’s nursery offerings are almost always “vegetatively reproduced” from softwood cuttings and are genetically identical to their parents.

(If you’re looking for a smaller upright pine, consider either Swiss stone pine (Pinus cembra) or limber pine (Pinus flexilis). Both are dense and slow growing and ideal for a smaller landscape.)

The brownish-grey bark is covered with bumpy stumps – from which older needle bundles have fallen. The green needles, in bundles of two, are rigid, slightly curved, and retained for five years or more. Their tips sometimes become yellow-green in winter. The small round cones have prickles on their scales.

Mugo pines prefer a deep loam soil but are quite adaptable, growing well in heavy clay as well as sandy soils. They are at their best in full sun. Those growing in partial shade, are often less compact. Once established, they are quite drought-tolerant.

For a denser, more compact appearance, they should be pruned each spring once the “candles” have fully elongated but before the needles have begun to emerge laterally. At least 6 mm (1/4 in.) of the candle should be left.

Larger varieties are used in mixed or shrub borders, foundations, and for mass plantings, while dwarf ones are ideal for rock gardens or perennial borders.

The species and older subspecies such as mughus and pumilo, are generally seed grown and often from different strains of seed. What’s available is a dog’s breakfast, complicated by the fact that many of these may have been pruned to look cute and dense, but will eventually grow up to fulfill their genetic make-up. As well, differentiating between var. mughus and var. pumilo depends on their flower (cone) characteristics, not on size or form. In contrast, most cultivars are dwarf, vegetatively propagated and uniform.

•   Pinus mugo mughus is a low growing form from the eastern Alps and Balkans, usually about 1.5-4 m tall and 1.5 to 3 m wide (5-13 x 5-10 ft.), but variable depending on the seed source.
•   Pinus mugo pumilio, also from the mountains of eastern and central Europe, is generally 1.5 m high and 1-2 wide (5 x 3-6 ft.), but variable if raised by seed.

The following varieties are vegetatively propagated and uniform:
• ‘Mops’ is compact and symmetrical with a neat mounded round form. Very slow growing, it is generally 1-1.2 m high with a 0.75-1.2 m spread (3-4 x 2.5-4 ft.).
• ‘Slowmound’ is low and dense, very slow growing, with rich green foliage (1.2 x 2 m / 4 x 6 ft.)
• ‘Compacta’ is dense and globular (2 x 4.6 m / 10 x 15 ft)

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, www.worldwideecotours.com]

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events

Sara Williams and Jackie Bantle
Saskatchewan Perennial Society
If you haven’t seeded your beets in the garden, it’s not too late. Beets (Beta vulgaris) are one of those root vegetables that can be seeded early in May but because of their relatively short growing season (55 days or so), they can be seeded as late as mid-July for a fall harvest.
Beets are a member of the goosefoot family (Chenopodiacea) because their leaves were supposed to resemble those of geese. The word beet is from the Celtic word, bett, meaning red.
For those of us who make beet leaf “roll-ups” stuffed with rice, it’s reassuring to learn that beets were indeed first cultivated for their leaves rather than their roots, as seen in 8th century BC cuneiform tablets from Babylon. They were well established in the Mediterranean region by Greek classical times where they were used medicinally and for flavouring.
The large roots that we use today were not known until the Christian era. Beets gradually spread through Europe where they were first called “Roman beets”, indicating that the swollen red taproots had been developed and introduced from Italy during the Roman era.
In his 1597 Herbal, Gerard wrote that “The greater red bet or Roman beet, boyled and eaten with oyle, vinegre and pepper, is a most excellent and delicate salad.”
These early beets tended to be coarse, misshapen and hairy. The smaller globes were not developed until the 1800s. By 1828, four varieties were listed in American seed catalogues. ‘Detroit Dark Red’, still a favourite today, was first listed in an American catalogue in 1892.
Beets can be seeded early in spring although if seedlings experience many days of cool weather (5°C or below), this may encourage plants to bolt, forming flowers and seed heads instead of good sized roots. Extreme heat in summer can also cause bolting. Plant beet seeds 5 mm deep, either in a scatter row or 30-45 cm between rows. Thin plants to 5-7.5cm spacings within the row. There is no need to ‘hill’ beet roots with soil if they push out of the ground; the feeder roots remain below ground.
Staggered plantings for beets are recommended to provide a long harvest period of tender, juicy roots: older beet roots tend to be oversized and may also have a tough, woody texture. By seeding a new row of beets 2-3 weeks apart until mid-July, one can ensure that the beets you harvest will have excellent texture and flavor right through to fall.
Young beet seedling leaves are a favorite of sparrows: don’t be surprised to see your morning beet seedlings disappear by the time you come home from work in the late afternoon. To prevent bird damage, cover beet rows with crop covers or supported bird netting early in the season.
Beet roots come in a variety of colours; from red to striped white and red, pink, black to orangish yellow and white. The flavour among all of the beet types is very similar. Beets that are used to make sugar (ie. sugar beets) are different than garden beets. Sugar beets have a sugar content of 15-20% and are a long season crop whereas garden beets usually contain only 5% sugar content. Garden beets are not only grown for their edible root but they can also be grown for their edible leaves; used in salads and beet-dough roll-ups. ‘First Crop’ and ‘Early Wonder Top’ are two beet cultivars recommended for their large, flavourful leaves.
Beet harvest can start as soon as roots are the size that you desire. Most beet roots have reached their prime flavor when they are 5-7.5cm in width. Cut petioles at approximately 4 cm above the top of the root. As with all root crops, do not cut off the root at the bottom as this will lead to desiccation in storage as well as beet ‘bleeding’. Beets will tolerate some autumn frost and will sweeten up with cool autumn temperatures.
Ideal storage conditions for beets are just above 0°C and high humidity. Storing root crops in a plastic bag in a fridge or in moist sand in your garage (just above 0°C) are good locations. Remove excess soil before storage. If you must wash roots before storage, wash gently: new wounds will encourage bacterial rots.
Betacyanin, the pigment responsible for the red colour, is extremely water soluble. Which is why borscht is red. And in some individuals, lacking the requisite genes to properly metabolize betacyanin, beets turn their urine pink.

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]. Jackie Bantle is horticulturist living on an acreage north of Saskatoon.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events. The Spring Plant Exchange will be held on Sunday, May 29. The plant exchange will start around two o’clock for more information please see the website. These are “member only” events, but memberships are available at the door for $10.00.

Saskatchewan Perennial Society
Popeye the sailor man, invented by Elzie Crisler Segar, first appeared as a comic strip character in 1929. By 1932, Popeye was telling the world about spinach. Placed in a hopeless situation, a can of spinach would miraculously appear. Popeye would quickly consume its contents, gain superhuman strength and save the day. Thus, several generations of children were told by their parents to “eat their spinach.” Thankfully, frozen and fresh spinach are now available through our prairie winters and it is easily grown in our gardens. Spinach is an excellent source of vitamin C, high in calcium, magnesium, potassium, a good plant based source of iron and is one of the earliest vegetables to seed in the garden.
The genus name may have been derived from isfanakh, a Persian word for “green hand.” Spinacia is from the Medieval Latin, probably originating from the Latin word spina, referring to the spiny seeds. Oleracea means vegetable-like.
Our garden spinach (Spinacia oleracea) is believed to have developed from a wild form, Spinacia tetranda, still found in the Caucasus, Iran and Afghanistan. It was first cultivated by the Persians (in what is modern Iran) and 647AD had spread via Nepal to China. It was brought to Spain by the Moors. By 1351, it was common enough that “spinachium” had appeared on a list of food that monks were permitted to consume on fast days. In his Herbal of 1597, John Gerard in England described it as “watery and tasteless,” but wrote that it would be good for those with a hoarse voice or who had trouble breathing.
Spinach can be seeded early in spring, as soon as the ground is thawed: plants can withstand a few degrees of frost. Sow seeds 1.5-2 cm deep. For full sized spinach plants, space rows 30cm apart. For baby spinach leaves, rows can be closer together or scattered in a 30-60cm wide bed. With air temperatures above 10°C, seedlings should emerge in several days. Depending on the cultivar, baby spinach leaves will be ready for harvest in as little as 4 weeks after sowing.

Spinach can be grown as a ‘cut and come again’ crop ie. that means that spinach can be cut again and again and leaves will grow back from the same roots. When spinach is grown as a ‘cut and come again’ crop, it is usually harvested as baby spinach and can be grown as close as 3-4cm apart. To produce full sized spinach leaves, thin plants to 7-10cm between plants. Harvest spinach leaves by cutting petioles with a sharp knife just above the soil line.

Because spinach is such a fast grower, consider doing multiple plantings throughout the growing season for a consistent supply. Seed a short row every 2 weeks from early May to mid-August. Plants that are seeded between July 1st and August 15th may need to be harvested as baby spinach as spinach tends to bolt (flower) under high day temperatures. Bolting spinach as been a problem as long as spinach has been grown. In 1784, the D. Landreth Seed Company in United States had developed a slow-bolting spinach variety called ‘Bloomsdale’ which is still available today.

When purchasing spinach seed, gardeners may encounter three different types of spinach: savoy, semi-savoy or flat/smooth-leaf spinach. Although there is not much difference in the flavour or nutrient value of the different types; the leaf appearance is unique to each type. Savoy spinach has curly, crinkly leaves that are slightly thicker than other types. Semi-savoy spinach plants are slightly more upright and have less crinkly leaves than the savoy spinach types. As the name suggests, flat or smooth-leaf spinach has flat leaves. The flat leaves are the easiest type to wash: flat leafed spinach is the main type to be used in frozen spinach.

New Zealand spinach (Tetragonia tetragonioides) is a slightly vining leafy plant that produces copious amounts of greens during the summer: it is not a true spinach. New Zealand spinach requires warm temperatures and a longer time period for seeds to germinate as compared to Spinacea oleracea. New Zealand is sometimes referred to as perennial spinach however, it is not perennial on the Prairies.

Malabar spinach (Basella alba) is a perennial vining plant native to tropical areas of Africa and Asia. The leaves are oval to heart shaped, semi-succulent and mucilaginous when cooked. When eaten fresh, Malabar spinach is similar in flavour to Spinacia oleracea but with a slight peppery, citrus flavour. Malabar spinach is very frost sensitive and should be started indoors about 6 weeks prior to transplanting out for best results.

Recommended fresh spinach cultivars include: ‘Tyee’, ‘Space’, ‘Kolibri’ (baby type), ‘Escalade’, ‘Avon’

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, or www.worldwideecotours.com. Jackie Bantle is horticulturist living on an acreage north of Saskatoon.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events. The Spring Plant Exchange will be held on Sunday, May 29. The plant exchange will start around two o’clock for more information please see the website. These are “member only” events, but memberships are available at the door for $10.00.

The following pines are all native to North America. And with a little bit of care, all have been successfully grown on the prairies. All prefer full sun, a lighter, well trained soil, and a more protected location.

Limber pine (Pinus flexilis) is an alpine/subalpine species, often found in exposed areas in the foothills of the Rockies. Both the species name, flexilis, and the common name, limber pine, refer to the supple young branches that can be tied in knots. It was discovered by Edwin Jones, an American army doctor who accompanied an 1820 expedition to the Rocky Mountains.

Dense and pyramidal when young, it becomes rather broad and flat-topped with age (like many of us) developing a large and uneven crown. Single or multiple trunked, both the trunk and the branches appear thick in proportion to their length. The bark is a soft grey-green, later turning greyish-brown to black.

The needles, in bundles of five, are a dark blue-green, stiff and slightly curved, with three or four lines of stomata on each surface. They persist for 5 or 6 years, lending the tree is very dense appearance. The cylindrical and resinous cones are erect when young, becoming pendulous, hanging at right angles to the stem, once they mature. The edible seeds can be eaten raw, roasted or ground into flour. Although slow growing, limber pines can live for over a hundred years.

They prefer a light soil but are quite adaptable as long as it is reasonably well drained. They’ll grow in sun or partial shade, are drought-tolerant once established, and have no problems other than the occasional sapsuckers who seem to find them attractive. Limber pines are well used as specimens, accents or within a mixed border.

Ponderosa pine (Pinus ponderosa var. scopulorum) is native to South Dakota’s Black Hills, eastern Wyoming and the Rocky Mountains’ eastern foothills. Ponderosa means heavy, a reference to the wood, while scopulorum means of cliffs or rocks, describing its native habitat. It’s smaller and hardier that the species (P. ponderosa) and better adapted to the prairies. Broadly pyramidal (15 x 6 m / 50 x 20 ft.), its bark is dark grey, nearly black. The needles are very sharp and in bundles of three. The brown cones are round, and each scale has a tiny bristle. Obtain trees from seed collected from its northern-most range.

White pine (Pinus strobus), native to much of central and eastern North America, including Manitoba’s southeastern corner, is probably the softest and most sensuous pine available to prairie gardeners. The species name, strobus, refers to its cones.

A valuable softwood lumber tree, during the colonial era white pine was reserved by law for the exclusive use of the Royal Navy for ship masts. Today, it makes a handsome specimen tree. Place it were it can be touched!

But be aware of provenance, the extent of a plant’s native range! Plants grown from seed that originate in the most northern and western portion of its natural range are more likely to be hardy on the prairies than those from further east or south. My own white pine came as a seedling, dug by a friend from the ditch on the highway west of Thunder Bay. It has grown and prospered for four decades, whereas two earlier attempts with commercially available white pines of unknown seed origin had failed.

White pines are graceful, pyramidal trees (15 x 7 m / 50 x 23 ft.) with thin gray bark that becomes brown and furrowed with age. The long, soft pliable blue-green needles are in bundles of five, point forward to the tips of the branches, and generally remain on the tree for two years. The curved cones are long and cylindrical, an attractive lilac-purple, exude a white resin and are retained for two years.

Fast growing, especially when young, white pines live for well over a century. Place them where they’re sheltered from wind as they are vulnerable to winter browning, more so in their early years. Somewhat adaptable, they do well on fertile, moist, well-drained soil in full sun or partial shade.

Although white pine blister rust and white pine weevils are serious concerns where large populations of white pines exist, neither has been very problematic on the prairies where these pines are relatively uncommon.

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 to France this September [Contact Ruth at 1-888-778-2378, www.worldwideecotours.com]

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events. The Spring Plant Exchange will be held on Sunday, May 29. The plant exchange will start around two o’clock for more information please see the website. These are “member only” events, but memberships are available at the door for $10.00.

Jackie Bantle and Sara Williams
Saskatchewan Perennial Society

Asparagus (Asparagus officinalis) is a perennial vegetable that is easily grown on the Prairies despite being native to the Mediterranean areas of Europe, northwest Africa and Asia. Called “sparrow grass” by many (including Shakespeare and Sara’s Dad when she was a kid), both the common and generic names are from the Greek word asparagos or sparago which means turgid or full to bursting – an allusion to its supposed phallic properties.
The species name, officinalis, is from a Medieval Latin term denoting plants used in medicine, herbalism and cookery. Hippocrates, the Greek physician considered the “Father of Medicine’, alludes to the use of asparagus as an aphrodisiac, possibly because of its phallic appearance. (Yet he also advised it as a treatment for diarrhea.) During the Middle Ages, monks grew it in abbeys and monasteries. Europeans of the Renaissance swore by it as an aphrodisiac and the church banned it from nunneries. The English herbalist Gerard (1633) likewise said eating asparagus was thought to increase seed (semen) and provoke lust.

Asparagus plants are dioecious: this means that each plant is either a male or female plant. Older asparagus cultivars (such as ‘Martha Washington’ and ‘Viking’) have both male and female plants. The female plants produce small red berries which are eaten and transported by birds, enabling asparagus to become an invasive weed in natural areas throughout Saskatchewan. Gardeners should avoid older asparagus varieties that produce female plants. More recent recommended seedless male asparagus varieties are ‘Guelph Millennium’, ‘Guelph Thiessen’, ‘Jersey Supreme’ and ‘Jersey Giant’.
An asparagus garden patch can be directly seeded outdoors, transplanted as seedlings or started with established asparagus crowns. Avoid direct seeding and begin seedlings indoors in late winter/early spring. Seed is slow to germinate and plants are very tender and fragile when they emerge.
Asparagus crowns, the roots of the asparagus plant, can be purchased from your favorite seed catalogue or local nursery. Beware that there is a risk of planting diseased crowns. Fusarium crown rot is a devastating disease that can destroy an asparagus patch and render your soil uninhabitable to asparagus for years. There is no certification program to ensure that asparagus crowns are ‘fusarium free’.
Because asparagus is a perennial, prepare the soil with care and attention. If possible, choose an area with well-drained loam to sandy loam soil. Prior to planting, incorporate a layer of well-rotted manure (at least 5 cm thick) into the soil. Plant the asparagus as soon as the soil has thawed and can be easily worked. Dig a trench at least 20cm deep. Plant seeds, crowns or transplants in the trench, covering with 5cm of soil. As the growing season progresses, fill in the furrow a little every few weeks, covering part of the plant but never burying the entire crown. By the end of the growing season, the trench should be level with the surrounding soil. Space the plants 30 cm within-the-row and 2m between rows.
To establish a strong, healthy asparagus patch, refrain from harvesting any spears until the plants are at least 3 years old. Premature harvesting decreases the vigor and health of developing crowns. In year 3, harvest up to 2 spears per plant. In year 4, harvest spears for 4-5 weeks. In year 5, harvest for 6-8 weeks. A good rule of thumb is to stop harvesting when spear diameter is less than 10mm (3/8 in.). Spears should be harvested when they are 10-20cm (4-10 in.) in length. Older spears will be fibrous. Cut spears up to 5cm below the soil line. Asparagus harvest occurs from spring until mid-June, then allowing plants to form a ferny hedge for the remainder of the growing season.
After asparagus ferns turn yellow and die in the fall, the ferns should be mowed or removed from the patch. In northern latitudes we tend to leave asparagus ferns in place over winter to catch snow. This is not recommended if you have a problem with asparagus beetles such as the common asparagus beetle (Crioceris asparagi) or the spotted asparagus beetle, (Crioceris duodecimpunctata).
In 1781, Benjamin Franklin wrote that “A few Stems of Asparagus eaten, shall give our Urine a disagreeable odour…” This was echoed by Marcel Proust, the French novelist in 1913 when he noted, perhaps with sarcasm, that it “…transforms my chamber-pot into a flask of perfume.” So, why does your urine smell after eating asparagus? Asparagusic acid is broken down into sulfur containing by-products. When you pee, these evaporate almost immediately, causing that unpleasant scent.

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 to France this September [Contact Ruth at 1-888-778-2378, www.worldwideecotours.com]. Jackie Bantle is horticulturist living on an acreage north of Saskatoon. This column is provided courtesy of the Saskatchewan Perennial Society. Check out their website at www.saskperennial.ca or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events. The Spring Plant Exchange will be held on Sunday, May 29. The plant exchange will start around two o’clock for more information please see the website. These are “member only” events, but memberships are available at the door for $10.00.

Jill Thomson

Saskatchewan Perennial Society

Dutch Elm Disease (DED) has been with us for many years. It is thought to have originated in Southeast Asia, travelled to Europe in the late 1800s, and was first observed in North America in 1930. It was found in Quebec in 1944, and has since moved across Canada, being found in Manitoba and Saskatchewan in the 1970s and 80s.  In Saskatchewan, the disease has travelled west along natural corridors of native elms that grow beside waterways such as Carrot River in the north and the Qu’Appelle valley in the south.

It is particularly important to keep the disease out of our urban areas because elms are invaluable shade trees that line our city streets – there are few trees that are as long-lived, sturdy and hardy. Some cities like Winnipeg have lost nearly all their elms and the city takes extreme measures to save the few that remain. Infected trees were identified in Saskatoon in 2015, 2020 and 2021. In Regina, it first appeared in 1981 and has popped up sporadically since.

The disease is caused by Ophiostoma ulmi, a fungus that clogs the water and nutrient transport tissues in the elm tree, killing branches and ultimately the whole tree. The fungus spreads from tree to tree by spores that cling to elm bark beetles. The spore-laden beetles bore into dead or dying elm wood to make cavities where they lay their eggs. Spores get dislodged inside the tree during this process, and fungal infection develops. The insect eggs hatch into larvae and feed inside the tree. They eventually emerge as mature beetles, which will likely be coated with fungal spores that can then be spread to other trees during egg-laying. This complex life cycle provides several points that allow us to reduce or prevent infection.

Many dollars have been spent to try and contain DED. The City of Saskatoon Parks Department has a crew dedicated to DED surveillance and testing during the season. The City also has programs for distributing educational materials, DED inspections, permits, specialized pruning schedules and monitoring. Additional budget resources are provided to promptly remove and dispose of infected trees when a positive infection is detected in the community. Infected trees in Saskatoon are removed immediately, chipped, and disposed of in the landfill. Neighbouring trees are monitored for up to 4 years to make sure that the disease hasn’t spread. There is also funding for educating the public on ways to recognize and deal with diseased trees. 

Pruning elms at the correct time is critical to remove the dead or dying branches that are attractive egg-laying sites. The provincial elm pruning ban runs from April 1 to August 31; this coincides with the elm bark beetle’s egg-laying period. However, if infected trees are identified during spring and summer they are removed immediately, chipped and disposed of in the landfill site (not as compost waste).

Several years ago, in April, we noticed a broken elm branch above our garage, that was likely to fall and damage the roof. Also the same tree had branches overhanging and brushing against our neighbour’s roof, with the potential to damage the shingles. We contacted the city, and within 24 hours an inspector came to assess our tree. He wrote a permit which allowed us to prune specific branches, with instructions for the correct disposal of material (chipping on site and transfer to landfill in covered transport). This prompt response ensured the potential hazard was removed quickly, and no dying branches or cut wood offered an egg-laying site for the beetles.

Another way to minimize spread of the disease is to dispose of any dead elm wood correctly and not to use as fire wood. Storing and transporting elm wood is prohibited by provincial regulation at any time of the year.  

In order to prevent DED from ruining our urban landscape it is important to follow these guidelines:

          •        Keep your elms healthy by pruning dying or dead branches during September 1 – March 31.

          •        Dispose of elm wood by chipping and taking to landfill.

          •        Do not store or move elm wood.

          •        If you see signs of DED (such as large, dead branches or individual branches with wilting and browning leaves that do not fall off in the summer), report them to your municipal authority.

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; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.

Sara Williams

Saskatchewan Perennial Society

Scots pine and Swiss stone pine are from Europe but have grown well here for generations. It’s always a horticultural high point to see a plant you’ve long loved in its natural habitat. I’ve been fortunate to see natural forests of both of these. And seedlings of Scots pines planted three and four decades ago have now grown to form their own forest.

Scots pine (Pinus sylvestris) is among my favourite conifers. The species name, sylvestris, is from the Latin word silva meaning “of the forest” (just as the state of Pennsylvania means “of Penn’s woods”, referring to the Royal Charter given to William Penn).

 “Scots” is somewhat misleading as this species is a widely distributed pine with a native range from Scotland in the British Isles through Spain and into Siberia. Most of the Scots pines that have proven hardy on the prairies come from seed that originated in Scandinavia and northern Russia – not Scotland. The wood was once widely used for the masts of sailing ships as the resin slowed their decay. Scots pine are large (15 x 6 m / 50 x 2o ft.), fast growing and long lived.

Although they can be almost symmetrical and pyramid-like when young, they become more open and flat-topped as they mature, with all the character of a “Group of Seven” painting. Their bark is a very attractive foxy orange to reddish brown, later becoming rough and fissured. With age, they develop a deep and wide-spreading root system, especially when grown on sandy soils.

Needles are in bundles of two with a sharp point. They are blue-green, stiff and slightly twisted, often becoming yellow-green by late winter. The cones, pointing backward toward the trunk, are in clusters of two or three. They are retained for two years and then fall. They have no prickles on their scales but are rock hard and exceedingly tough on lawn mower blades – another good reason to apply mulch below these trees!

Scots pines do well on sandy, well-drained soil in full sun and are exceptionally drought-tolerant, even when fairly young. They are occasionally infested with white scale insects, and sap suckers have been known to leave their mark on them, but are otherwise trouble-free.

They are excellent as specimen trees (when perfectly formed and symmetrical) or as character trees (when not perfectly formed and asymmetrical), as well as in groupings. They have been planted in shelterbelts for nearly a century and are well appreciated by birds when used in wildlife plantings. They are xeriscape trees par excellence. [355]

Native to the Carpathian and Alps Mountains as well as parts of Asia, the Swiss stone pine (Pinus cembra) is long lived but very slow growing – it’s a tree you plant not for yourself but for future generations and your grandchildren.

Narrow, columnar, dense, and clothed to ground level (if not browsed by deer), it’s one of the loveliest pines available. Up to 12 m in height and 5 m wide (40 x 16 feet), the bark is gray-green and smooth. The long soft needles are dark green with bluish-white stomata lines on their undersides. In bundles of five, they’re resistant to sunscald and retained for up to 5 years, giving the tree a very dense appearance. The erect cones are greenish-violet when young, maturing to purple-brown. They are prickle-free with edible seeds (pine nuts) and drop in their third year without opening. Once on the ground, seeds are released through decay or dispersed by birds.

Plant in full sun in well drained loamy soil. Once established, they’re moderately drought-tolerant. Although it has a painfully slow growth rate from a gardener’s point of view, the Swiss stone pine is considered one of the best pines for a small landscape. Certainly, it will not outgrow its location in your lifetime. It’s excellent as an accent tree, as a grouping or in a mixed border.

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; saskperennial@hotmail.com ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.