By Mark and Ben Cullen – Gardening

Canadians have much to look forward to in the next few months: hockey, the Grey Cup, warm fires, skiing, backyard hockey rinks.  Gardeners get time off to consider their strategy for next season’s garden, but not until we have completed some important tasks.

Here is our short list of the most important gardening work as we begin to shut it down:

1. Put away.  You have an investment in a lot of stuff that does not age well when exposed to cold winter weather.  Put under cover, that is, in the garage, shed or some place out of the weather: garden hose, watering cans, hand tools and anything that is made of wood.  Wood rots fastest during the freeze/thaw cycles that the GTA is famous for.  Wood window boxes and furniture should not contact soil, which hastens rot.  
2. Lawn mower.  You will make the last cut soon if you have not already.  We use our power mower set to its highest setting to mulch leaves on the lawn until they are too thick to leave there to rot (here, rot is beneficial) when we rake the excess off the grass into the garden.  Then, we either empty the gas tank and change the oil of a power mower or put a stabilizer in it to keep it fresh come spring.  Clean and oil the cutting deck.  
3. Lay sod.  “The best performing sod we have laid is in November.  Come spring, it bounces back and takes root.”  Professional landscaper Simon Evans, Northscape Landscaping.  A pro has spoken.
4. Fertilize your lawn.  This sounds odd, but the most important application of lawn fertilizer is right now, just before the snow flies and the deep freeze arrives.  A fall application of lawn food strengthens the root zone for a fast and healthy green-up come spring.   
5. Leaves.  Forgive us for repeating something that we have expounded upon for a few years, but do not put your leaves out to the curb.  Instead, save work, expense, and money by raking leaves off your lawn onto your garden.  Mulching with a power mower increases the volume of leaves that you can manage in this way.  Or just pile them up in your compost bin.  Either way, they will rot down by mid spring, attract all kinds of beneficial insects and make your garden plants very happy.  Or you can rake them into large paper bags, drag them out to the curb to be picked up by a big diesel truck and buy soil or manure come spring.  Do what makes the most sense for you.
6. Plant tulips.  Last call!  Before heavy frost, tulips take well to our cold Canadian soil.  Most other spring flowering bulbs less so, as they generally need more time to put down a root before winter. 

What not to do:

1. Do not cut back ornamental grasses and perennials.  We leave ours standing all winter for two reasons.  One, they produce some winter interest as the snow gently lands on them during winter months and two, many beneficial insects, soil borne mycorrhizae and beneficial bacteria benefit from the duff material that falls from trees, shrubs, and perennials in the fall.  Avoid the temptation to sanitize your garden.  That works well for your bathroom but not your yard.
2. Do not trim your hydrangeas.  It seems most everyone with a garden now has a bed these large, late-season, flowering beauties.  Let them stand until April with the flowers intact.  They are much more interesting than the bunch of sticks that form the skeleton of a pruned hydrangea.
3. Do not prune maples, birch, or other hardwood trees while dormant.  After the leaves fall, they tend to bleed when spring arrives if pruned in the dormant season, weakening them.  Best to prune these trees when in full leaf. 

Enjoy your winter not gardening. Come spring, you will be refreshed and ready to create the garden of your dreams.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook.

By Mark and Ben Cullen – Gardening

Gardeners live in a world of change. As we gain experience, we pay more attention to changes in our gardens as we spend time there.   

At no time in the year is change more dramatic than now, during the change of colour in tree leaves and their drop to the ground. What is going on? And what happens to the leaves that we allow to remain in the garden, put in our compost or the ones that we mulch up with a power mower to rot on the lawn?  

• Colour. Let’s look at the role of leaves, from the point of view of the tree. They are green because chlorophyl courses under the tree bark and out to the leaves during the growing season. Trees absorb long-wavelength red and short-wavelength blue regions of light spectrum to produce chlorophyl but reflect green which is what gives leaves their appearance.  As the tree nutrients, and the sap carrying them, retreat to the root zone of the tree in the fall the chlorophyl is drained from the tree’s system. It is accurate to say that leaves do not change colour, but their true colours in the form of carotenoids pigments (orange yellow, present throughout the year) and anthocyanins (red purple, produced late in the season) are revealed in the absence of chlorophyl.
• Carbon. Fallen leaves are extremely rich in nutrients, particularly carbon. When environmentalists talk about the benefits of trees, they are acknowledging the process of sequestering carbon from the atmosphere as new growth wood and leaves. Carbon is captured from the atmosphere and stored in the tree.   As CO₂ is absorbed by the tree, oxygen is released in exchange. This quid pro quo arrangement is essential to human existence.   Try breathing without a fresh supply of oxygen and you will understand.
• Soil. Fallen leaves provide a foundation for good soil, largely thanks to their high concentration of carbon which forms the backbone of good soil health. Think of Southern Ontario before the Europeans arrived about 500 years ago, cloaked as it was in a thick cover of diverse deciduous trees.  Beneath this massive forest a thick layer of rotting leaves over 10,000 years old produced some of the finest quality soil in the world. One day a green, breathing leaf, soon a leaf falling to the earth like a wafer of fertilizer, a rotting host for beneficial bacteria, mycorrhiza and countless bugs and other living things in the bed made by the tree cover.  Sadly, this is what made much of southwestern Ontario so attractive for agriculture, leading to the large-scale clear cutting of these old growth forests. 
• Mulch. The benefits of mulch are well known; reduced erosion, retained moisture, and most importantly weed control. Why pay for coloured mulch when leaves, which are free, perform the same function? Besides, coloured mulch is unattractive anyway…not that this is an opinion column. 
• Compost. The high carbon content of leaves is useful for balancing nitrogen content of kitchen scraps in your composter. A good recipe is 5-10 parts brown material such as leaves and cardboard to 1-part green material such as kitchen scraps. This is, of course, after you have mulched all your garden beds with a generous layer of leaves and still have more. We will save the full benefits of compost for another column, but there is a reason why we call it black gold.
• Life. On a microscopic level, healthy soil is teeming with life, literally billions of living organisms in a single handful. Cascading up that web of life, leaf cover provides both food and shelter to visible lifeforms in the shape of worms, snails, and spiders which in turn provide fodder to birds, frogs, toads, and larger mammals. The difference between bare soil and one with leaf cover is night and day for the web of biodiversity.

Observing this season of change with a deeper perspective in mind, this colourful foray to decay in the autumn season leads to new life a plenty. Change we can embrace.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook.

By Mark and Ben Cullen – Gardening

Gardening is an evolution.  Canadians do not suddenly garden outdoors, then indoors over night.  You might be raking leaves one day and cleaning your hoya indoors the next, then planting a tree the following day. 

Your tropical plants are going through many changes, much like outdoor plants are.

The gradual reduction in day length is part of the system that creates a host of change for indoor plants.  Sunlight is less intense each day, as the earth tilts further from the sun.

Your furnace comes on to keep the house cozy for humans, drying the air and creating havoc for some tropical plants.  Certain insects come alive.

What to do?  Our advice:

1. Cut back on watering.  Almost all tropical plants require less water from now through March as they are growing slowly, if at all.  Test the need for water by pushing your finger into the soil up to your second knuckle.  If the soil is cool, it is damp enough for most plants.  When it is dry 2 to 3 centimetres deep, it is time for a drink.  Let the water move through the soil, into a saucer or your sink, then drain the excess away.  No tropical likes to sit in water for long: an invitation for root rot.
2. Fertilizer.  When a plant performs poorly, we often are tempted to reach for a fertilizer to “fix it”.   Resist.  The plant is speaking to you, and it is not saying that it is hungry.  It is more than likely telling you that it needs more sunlight, or it has an insect infestation.  Or you overwatered it, in which case re-read #1.
3. Insect infestations.  The three main enemies of tropical plants this time of year are mealy bugs, fungus gnats and spider mites.  Here is what we recommend for treatment:
   1. Mealy bugs.  Small, crawling insects that suck the goodness from tender stems and leaves.  One-centimetre-long flattened blobs that resemble cotton batten.  You can squish them with your fingers if you have the stomach for it.  Or, using a small artist’s paint brush, coat them in undiluted rubbing alcohol.  This will take some time on a big plant so you might want to turn on the tv while you do this job.
   1. Fungus gnats make themselves known while you read the newspaper, maybe even this article.  They love to divebomb the paper itself (sorry e-readers).  The other way to detect these tiny little “fruit flies” is to disturb the surface of the soil by scratching with a fork.  If a cloud of small, black flies descends, voila!  The solution is to cut way back on watering as fungus gnats are only interested in eating fungus that is growing in damp soil.  Starve the fungus, starve the gnats.  Continue to scratch the soil weekly until they disappear.
   1. Spider mites.  Tough ones.  Small red bugs about the size of a head of a pin.  You can detect them when leaves turn yellow, by placing white copy paper under the plant while you give it a shake.  The mites will fall onto the paper and contrast with it.  The best solution is to wipe the leaves of the plant down using a clean, soft rag that is soaked in insecticidal soap weekly.  If that does not work, place the pot in a plastic bag, tie the top to protect it from becoming overwatered and put the plant in a shower for 5 minutes or so.  Mites hate moisture and love dry air.  Do this weekly until you no longer detect the mites.
4. A tip for all indoor gardeners. The Canadian winter is long.  Remember, indoor plants are tropical.  They are used to the rain forest or desert, depending on their native home.  They did not originate inside of our homes.  Be patient with them and expect some dropped and yellowing leaves, as they acclimatize to their indoor winter environment, especially if they lived out of doors for the summer. 

Most tropical plants do not thrive in our winter conditions, they exist.  As indoor gardeners, we can only make this existence more comfortable for them.

By Mark and Ben Cullen – Gardening

Our opinion of what is beautiful can change.  Ben looks at the fashion of the 70’s and laughs at the gaudy colours, men in long unkempt hair, sideburns.  Hey, this was Mark back in the day.  Careful son!   

Milkweed has been in fashion for years.   Years ago, it was an enemy garden weed.  That is, until its relationship to the beloved monarch butterflies was brought to public attention. Today, we see milkweed seeds available for sale from most Canadian seed suppliers.  From noxious weed to $1.99 a packet of seed in one generation. 

This is a good thing – for the beautiful milkweed, for butterflies, for people and for the environment.

We believe goldenrod (Solidago spp.) is next to have its natural beauty redeemed in the court of public opinion.

One myth that plagues goldenrod is that people are allergic to it. The fact is ragweed is predominantly responsible for hay fever in much of North America. Goldenrod’s showy, pollen-rich yellow flowers happen to bloom in the same period. Guilt by association.  Goldenrod flowers are sticky and do not blow in the wind.

Golden rod has some phenomenal traits.

Of the 120 or so species within the Solidago genus, about 80 are native to North America. By our standards, native plants cannot be weeds – they are wildflowers.  See how we elevated their reputation just by changing the “w” word: from weeds to wildflowers?

Goldenrod herbal tea has been used as an anti-inflammatory medicine by First Nation communities since pre-settler times. Young goldenrod leaves are even edible on their own.

Humans aren’t the only ones who can consume goldenrod. Emily Damstra, a natural-science illustrator in Guelph, Ontario refers to goldenrod as “a biodiversity superhero”.

She explains, “Hundreds of different insect and spider species make use of goldenrod. One of my favourites is the caterpillar of the Goldenrod Hooded owlet moth—Cucullia asteroids. These lovely insects come in a few different colour morphs; I love encountering them because they’re like jewels hidden among the foliage and flowers. Goldenrod hosts many different caterpillar species, which is important because most of the terrestrial birds in North America feed their young primarily with caterpillars.”

Damstra spent a whole year studying goldenrod and the insects, spiders, and various other organisms supported by it, which culminated in three published articles and a whole series of scientific illustrations sold as artwork.   

Another point about goldenrod is its value year-round, as Damstra illustrates in her series. “When Goldenrod are at their peak in late summer, numerous bees and other pollinators will be the first animal life you’ll see. Later this fall, you can still find insect larvae in among the seeds, and small spiders on patrol. In winter, a variety of galls that goldenrod hosts are evident, and in spring, signs of leaf miners are abundant.”

Galls are one of Ben’s favourite features of the goldenrod – those are the bulb-like growths on the stem that are induced by larvae of different insect species. Parasitic wasps in turn lay their eggs in the larvae, which feed on the plant from inside these bulbs. It is not uncommon for woodpeckers to feed on the insects living inside the gall, another display of ecological theatre.

Cultivated varieties are increasingly common, most of which thrive in full sun and moderate soil types. Now is a good time to divide any existing bunches you might have. ‘Fireworks’ goldenrod (Solidago rugosa) is a cultivar with arching flowers that appear to burst as the name implies, and Blue-stemmed goldenrod (Solidago caesia) is unique for its partial shade tolerance – a bright way to colour in some darker corners of the garden.

Of course, you can always find goldrenrod naturalized in ditches and meadows across its native habitat. This is a good time of year to enjoy the last golden splendour of the season. They are often found among Queen Anne’s Lace and New England Aster – the white, purple and yellow playing well off of one another in the wild: art in nature. Online, you can find Emily Damstra’s illuminating illustrations and further reading on the genus at www.emilydamstra.com/projects/goldenrod/

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook.

By Mark and Ben Cullen – Gardening

We are all familiar with the message that we should buy locally produced food.  It is fresh, lacks the transportation impacts associated with long distance trucking and a locally grown apple this time of year just tastes better than any of the competitors.

But what about plants?  The nursery grown plants made available to us from early spring through late fall can originate from far away places, or they can be grown just down the road.  The difference is significant.

Here are our reasons why buying local, Canadian grown plants makes sense:

1. Winter hardiness.  Most plants that we grow in our gardens we expect to survive our long, cold Canadian winters.  A two-metre-tall Canadian grown tree that you buy at a garden retailer now was started 6 to 8 years ago from a seed or cutting.  It has endured several Canadian winters before you plunk it in your yard.  That preconditioning is no guarantee that it will survive in your garden, but it sure helps. 

Frequently we are asked, “what is the best cedar for hedging” and our answer often surprises people.  The nursery grown cedars grown locally are a much better bet than the cheap eye candy Emerald Cedars that are sold in black plastic pots and grown in Oregon.  They grow fast on the west coast.  Here, they die faster.  Their roots are too small to push through a hot, dry, Canadian summer, and if they live, they enter the winter hungry and tired. 

• Environmental costs.  When you buy a rose bush from California the cost of transportation is built into the retail price.  However, the environmental cost of shipping it over 6,000 kilometres is one that we all pay for in increased carbon.  The detrimental effects of burning carbon fuel are well documented by science and now, undisputed. 
• Jobs at home.  The Horticulture sector of the economy supports 220,000 Canadian jobs, according to the most recent Stats Can statistics as of 2019.  Since the pandemic, we are certain that the number of jobs has increased as has the farm gate value of Canadian grown ornamental plants.  According to Victor Santacruz, Executive Director of the Canadian Nursery Trades Association, the ornamental horticulture sector of the economy provides over $4 billion in employment income and $15 billion in economic impact on our economy. This is made up of over $7 billion in sales and approximately $8 billion in value added impact to the economy. 

In our opinion, there has never been a better time to buy Canadian plants.

• Community building. Especially of late, Master Gardener groups and horticulture societies have reported stellar success selling plant material grown by their members at plant sales. These groups do a lot of service in their communities, educating and promoting horticulture, and a purchase at their sales is an investment in your local horticulture community.
• Native biodiversity. A niche breed of nursery grower grows sells native seed-source perennials, an important point of difference from many commercial growers who produce genetically identical plants from cuttings. Seed-sourced native plants help protect native biodiversity by cultivating local genotypes within a species that are specifically adapted to their locales.

We reflect on the world that Ben’s baby Peter will inherit. What educational and job opportunities will exist for him in this sector of the economy? And what can we do to sustain and build on a profession and a planet that serves us back? Supporting local is an easy choice.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook.

Very soon we will be in awe of the leaf colours in our part of the world. 

Then, they fall to the ground. 

After deciduous trees drop their leaves, Canadians are left looking through bare tree branches at each other.  Your neighbours can now see into your kitchen (or worse) and your privacy is only protected by the cold space between your window and your neighbours. 

Unless you planted evergreens.

Evergreens do not drop their leaves as they have needles, which serve much the same function that leaves do during the growing months but come winter, they stay on the plant in a dormant state, waiting for spring.

We are not in favour of landscapes that are entirely evergreen (coniferous) or deciduous, but a thoughtful mix of the two.  Here are our top picks for Canadian gardens:

1. White Pine (Pinus strobus).  The tree that made Ontario famous, and the official tree of the province.  When the British arrived here, they saw the white pine evergreens that dominated the mixed hardwood forests and they wanted them to build the British navy, after they had cut down all the big trees in the U.K. for the same purpose.  While the original giant (virgin) pine is virtually gone, white pine is still a mighty fine choice for the landscape, especially where it is protected from prevailing northwest winds.  Soft, flexible needles, grows to 8 metres high and grows best in light sandy soil. 
2. Norway spruce (Picea abies) fast growing, classic Christmas tree shape.  Give lots of space as it matures to 5 metres wide at the bottom and 20 metres high.  Branches have a slightly drooping appearance.  If anyone asks if it is not well, tell them this is a special feature of the tree. 
3. Balsam Fir (Abies balsamea).   King of the Maritime Forest.  Prefers a moist, open soil, much as cedars do.  Soft needles with classic evergreen fragrance.  Grows to 20 metres high, 4 metres wide.  
4. Eastern Hemlock (Tsuga canadensis).  A large evergreen that performs well in the shade.  Another native to Central Canada.  Hemlock thrives in the dappled shade of the understory of deciduous forests.  Our experience has taught us that hemlock are best planted small.  A tree more than a metre high does not transplant well and takes longer to grow than a shorter version, purchased for less money by someone with a little more patience.  Matures to 20 metres high and 8 metres wide, when given enough room.  Hemlock lends itself to pruning if you wish to contain it.
5. Junipers.  There are hundreds of junipers to choose from and the Sheridan Nurseries Garden Guide states that, “there is a juniper for every garden”.  Mark was raised on junipers but now he is grown up he believes that there is no juniper for his garden.  We cannot let his personal taste (or lack of it) get in the way of good garden design.  There are very low, prostrate varieties like Dwarf Japanese Garden (Juniperus procumbens ‘Nana’) and tall, upright specimens like Mountbatten, a fast-growing Canadian introduction that matures to 6 metres tall and 2 metres wide.  All junipers need sun and are prickly to handle.  Mark reminds us to wear gloves.
6. Yews (Taxus).  A versatile, slow growing evergreen that creates great hedges or specimens that can be pruned into lollipops or owls or whatever your heart desires.   Pyramid Japanese yew is the classic foundation plant.  Featuring deep green colour and generally good shade tolerance, yews enjoy dry, well drained soil. 

When you go shopping for evergreens be sure to pay close attention to the ultimate height on the label.  A dwarf Alberta spruce is not what we call dwarf as it matures to about 2.5 metres.  Avoid Scots Pine (Pinus sylvestris) as it is thin, straggly and has a rangy, discombobulated growth habit.  But it looks great in its native Scottish highland.

If you have a Scottish background you might want to plant one for posterity. Too bad about your plunging property value though.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook