Category Archives: Shrubs & Trees

Tree Identification with a Winter Key

By Laura Gardner, Master Gardener

Plant apps can be useful identification tools but their accuracy often depends on the quality of the photos and the features that are being examined. They tend to work best with more unique features such as fruit or flowers. I find that as a learning tool they can be limited because they do not give the user details about how or why the particular species was suggested. There are some other tools that can lead to an identification as well as help hone identification skills.

There is a little book called Winter Tree Finder by May Theilgaard Watts and Tom Watts. Originally published in 1970 and at only 58 pages, it is the perfect size to take into the garden or on nature walks. Known as a dichotomous key, it covers deciduous trees of the Eastern US and Canada and provides maps that show the various species ranges. Dichotomous keys lead you along a path towards the correct species by asking a series of questions about the tree’s various parts. This particular key relies mainly on the appearance and arrangement of terminal and lateral buds on twigs, twig width, bud scales, and vein or vascular bundle scars for identification. Other features may also be considered such as lenticels (pores), bark colour, pith (tissue inside twig), fruit, thorns, etc. It also includes a ruler on the back cover that is used to measure the width of the twigs.

There is a tree that is growing on my neighbour’s property that I know is Acer negundo (Manitoba Maple) and I decided to see if this book could identify it. I pruned a twig that was hanging over on my side of the fence. If you wish to identify other trees that are not on your property, it is appropriate to take photos, take a guidebook or key with you, or get permission to take a cutting.

Step 1: I noted whether the leaf scars are in an opposite or alternate arrangement (phyllotaxy) on the twig and if they were in pairs or were more numerous (whorled). Leaf scars are the markings on the twig where the leaf stalk was attached before it dropped off in the fall. In the case of my tree, there was an opposite arrangement and paired leaf scars.

Step 2: I looked at the width of the twig—less than 0.25” or greater than .25” In this case, the twig was no greater than 0.25.”

Step 3: I examined the texture of the terminal bud and the shape and the number of old vascular bundles or vein scars. Old vascular bundles represent the xylem and phloem (ports or channels) where water had flowed to the leaves. Since the terminal bud was not rough and dry, is conical, and the leaf scars had three bundles and were somewhat V-shaped, the twig belongs to the genus Acer (Maple).

Step 4: I considered the colour of the buds. The key asked if the buds were red, reddish brown or not. These buds might be seen as reddish brown and so could lead one down the path towards a different species but they also were “whitish and woolly” and the twigs were “purplish.” The leaf scars also met at a point on the twig. These combined features pointed towards A. negundo (Manitoba Maple). Colour variability within a species might question an identification. Also bear in mind that these types of guides may not identify exact cultivars or hybrids. But since this exercise, I now see this tree everywhere on my winter walks.

Other Similar Books

Fruit Key and Twig Key to Trees and Shrubs by William M. Harlow

The Shrub Identification Book and The Tree Identification Book by George W. Symonds

Woody Plants in Winter by Core and Ammons (also online through Archive.org as an eBook.)

Online Sources

University of Wisconsin K-12 Forestry Education Program: https://www3.uwsp.edu/cnr-ap/leaf/Pages/LEAF-Tree-Identification-Cards.aspx

An excellent web site of winter tree photos can be found at http://www.portraitoftheearth.com/trees/specieslist.html

Foraging for Winter Décor

By Marilyn Homewood, Master Gardener

As we enter the holiday season, the time has come to start collecting some of nature’s bounty to create seasonal trimmings for your home.  Much of this bounty is right under our noses and can be gathered easily. Foraging should begin at home on your own property.  It is surprising at what you can find in your own garden not just in terms of evergreens but also dried material such as seed pods.  For those items not immediately on your doorstep, look elsewhere where you have the permission (I visit friends for a few snips of things from their gardens) or forage on public spaces such as roadsides.  Remember to harvest sustainably taking only what you will use and take minimum amounts from each plant.  When harvesting boughs, only use trees larger than 6 feet and cut your boughs 2-4 feet from the tip of a branch and above a node to encourage regeneration. Make it look like you were never there.

Swag on potting shed

Cedar, white pine, white spruce and scotch pine can be found in abundance locally but don’t overlook the junipers (I like to use wild junipers), yews and euonymus.  Fir is really nice but more difficult to source in my area but it is available for purchase.

Boughs can be used as garlands or in planters.  The soil in the planter acts as a source of moisture until freeze up and also stabilizes the display.  Conifer branches can also be cut down to be used in table arrangements or in wreaths.  For arrangements kept indoors, fill the container with a mixture of potting mix and vermiculite and keep damp to prevent needle drop. 

Winter wreath

Woodies: Two species that are used extensively in this area are white birch and red osier dogwood.  Both provide colour contrast and add a structural element.  I keep my birch from year to year so only had to source once. Birch is available for purchase at many stores.  Dogwood is available anywhere it is moist so remember to be mindful of your footwear when foraging.

This arrangement lasted 6 weeks before the needles began to drop

What says the holidays better than pinecones?  They come in many different sizes and shapes depending on their species.  Closed cones can be opened by placing on a cookie sheet and baking at 250 degrees for 1 hour.  Cones can be used as accents in planters/arrangements/wreaths or by filling bowls full of them.  I have dipped the edges of my pinecones in white craft paint so they appear to be snowtipped.

Other additions to my gatherings include seedpods from Siberian iris and oriental poppy, seedheads from coneflowers and penstemon and dried allium heads.  Some types of perennial foliage such as that from Heuchera “Palace Purple” and the Penstemon “Dark Towers” is long lasting and adds interesting contrast to an arrangement. I also used some of my dried hydrangea in the planters.

Coneflower in planter helps to provide winter interest

Berries add a nice pop of colour and it is hard to beat those from the winterberry bush (Ontario’s native holly, Ilex verticulata) but these are not commonly found wild in this area due to our higher soil pH. Some of the local nurseries and florists have it available for sale however.  I do purchase some for my planters, for my wreath, I use the berries from the choke cherry bush (Prunus virginiana).  The bright red berries retain their colour throughout the entire winter and are not eaten by the birds (unlike the berries from the grey dogwood that were eaten after the first cold night).

When you’re done, if you still crave more variety, local nurseries have greens and other decorations available for sale.  For ideas on how to use what you collected, go no further than YouTube and Instagram.  One of my personal favorites are the Instagram live sessions done by Claus Dalby (Denmark’s version of Monty Don). They are posted to his IG page (clausdalby) as “Master Classes in Nordic Christmas”. It is a great source of inspiration and puts one in the holiday mood.

Not into foraging? Visit your local nursery. The offerings are astonishing!

Winter planter after a snowstorm

Winter: When Bunnies Can Wreak Mortal Havoc on Gardens

By Mary-Jane Pilgrim, Master Gardener

Two weeks ago, MG Lois Scott wrote an article about Burning Bush (Euonymous alatus) and other invasives now on the Invasive Species lists that she is eradicating from her gardens in favour of natives. I actually used to have a beautiful Burning Bush, right at the front of my garden. And then winter came, and a furry rodent.

Rabbits might look cute and fluffy, but they’re not a welcome sight for gardeners; especially between December and March. As cute as they might be, they can cause serious damage to plants in the winter when greens aren’t available for them to easily munch on.

Pretty sure that Bugs Bunny, who we could see in the snow through the living room window, caused the demise of the burning bush. In the spring, it didn’t bud. Most of the outer bark was missing and tooth marks were very evident. It was as dead as a doornail. (Aside: “Dead as a doornail” is one of the oldest idioms found in print, going back to the 14th century. It referred to nails having been pounded through a door, and having the pointed end pounded flat against the door. That nail could not be reused!)

Back to my story. Apparently, our neighbourhood cottontail had made a lunch or dinner (or several of each) out of the soft bark on our small burning bush shrub and also my prized “Perry’s Gold” pine (Picea abies ‘Perry’s Gold’), purchased from Anna’s Perennials; my favourite local garden centre. Sigh. Happily, Anna had another one for me.

Obviously, rabbits don’t hibernate. When winter arrives and greens disappear, they turn to nibbling on the bark of young trees such as birch, crabapple, mountain ash, honey locust, willow and oak. Older trees with their thick rough bark aren’t as tempting as a young tree where the bark is smooth and thin. Green food material is just under the surface of young trees.

The rabbit’s menu also includes bushes/shrubs, such as roses, sumac, Japanese Barberry, viburnum, Burning Bush, Rose of Sharon, arborvitae/cedars and other broadleaf evergreens. It’s all about survival and they won’t be picky when their populations are high. Once a rabbit has chewed the outer bark of a small tree or shrub, little can be done to save it.

While I feel for the starving rabbits out there, there are a few preemptive steps you can take to stop rabbits from wreaking mortality havoc in your gardens. The most effective is to place chicken wire fencing around vulnerable plants like a cylinder. The fencing material needs to be high enough that rabbits won’t be able to climb or reach over the fence after a heavy snow. In most cases, a fence that stands 2-3 ft should be sufficient. To prevent them from crawling underneath the fencing, pin the fencing to the soil with U-shaped anchor pins.

Small trees can also be protected by placing white spiral tree guards around their trunks or by wrapping them/their trunks in burlap. Damage may be further reduced by removing brush, junk piles and other places where rabbits live and hide from around your home.

Lastly, there are a few plants that rabbits seem to find less appealing, particularly plants with thick or prickly leaves, and plants with very strong scents. It may be worth it to experiment around your prized shrubs with hellebores, foxgloves, allium, acanthus (bear’s breeches), and salvia (sage).

A final parting note: One or two rabbits that overwinter in your garden this year could mean dozens returning to munch on your prized shrubs next winter, given the fertility of these furry rodents!

Insect Galls on Trees

By Laura Gardner, Master Gardener in Training

I was out for a walk earlier this summer and noticed that a number of trees in my neighbourhood have lumps on their leaves, leaf stalks, shoots, or at the ends of their branches. At first glance you might be alarmed and think they are diseased, but many are the homes of tiny insects such as aphids, mites, sawflies, psyllids, and midges. They are often quite numerous and they come in different shapes and sizes. A gall is formed through the expansion of plant cells—similar to a tumour. This may be triggered by organisms such as viruses, bacteria, fungi, nematodes, or insects. Insects induce the galls through actions such as oviposition (inserting the egg into the plant tissue), the release of chemicals by the female and eggs, and through feeding. It is a shelter for the young and protects them from predators. While sometimes causing leaf deformity, in the majority of cases, galls are a cosmetic concern and do not harm the tree.

Here are a few you may encounter that are caused by insects:

These variable shaped galls specific to Populus deltoids (Eastern cottonwood) are the homes of an aphid called Mordwilkoja vagabunda (Poplar Vagabond Aphid). New galls are a light colour but become darker with age. Each gall releases upwards of 2,000-winged offspring in mid-July to early August. Sounds like it could have been the inspiration for a science fiction novel or movie.

Rabdophaga strobiloides (Willow Pinecone Gall Midge) are found at the ends of branches of various Salix spp. (Willow). What is amazing about these structures is that up to 31 different insects use them for their young—residing in the papery-like folds of the gall.[i] The galls are also frequently predated by birds and parasitic wasps.[ii] The biodiversity that Willows support is wide and for this they are known to be keystone species—they are also among the earliest plants to flower in the spring and support emerging pollinators like Queen Bumblebees.

Euura proxima (Willow Redgall Sawfly) frequents certain Salix spp. (Willow). This gall can be identified by its red bean-like appearance on the leaves. Sawfly larvae are often mistaken for Butterfly or Moth caterpillars. They can be distinguished by the number of abdominal prolegs: the former has six or more and the latter five or less.

Pachypsylla celtidismamma (Hackberry Nipple Gall Maker) is a Psyllid (Jumping Plant Lice) that forms round, often clustered galls on the underside of Celtis (Hackberry) trees. Adults spend the winter in cracks of the tree bark itself or even in nearby buildings.

The Eriophyid mite, Vasates quadripedes (Maple Bladder Gall) forms on Acer spp (Maple) such as the upper leaves of this Acer x freemanii ‘Autumn Blaze’ (Freeman Maple ‘Autumn Blaze’). The galls first appear as green, then turn to red, and finally black. The mites overwinter in the creases of the tree’s bark.

So, if your trees have strange growths on them, check out the wonderful web site https://gallformers.org. There you can identify galls by their specific host trees, the form of the galls, and their location on the trees. You can also narrow your search down to those that occur in Ontario. Another good site for identification is https://www.bugguide.net, a comprehensive database of insects for the US and Canada.


[i] Willow Pinecone Gall Midge. Minnesota Seasons. http://www.minnesotaseasons.com/Insects/willow_pinecone_gall_midge.html#:~:text=It%20consists%20of%20numerous%2C%20stunted,shape%20resembles%20a%20pine%20cone

[ii] Van Hezewijk, B.H. and Roland, J. (2003), Gall size determines the structure of the Rabdophaga strobiloides host–parasitoid community. Ecological Entomology, 28: 593-603. https://doi.org/10.1046/j.1365-2311.2003.00553.x

Google Lens (free!) for all of your identification needs

By Mary-Jane Pilgrim, Master Gardener

If you’re outside enjoying the fresh air, and happen across a flower or bird or insect and you’re not sure what you’re looking at, a new feature from Google can help you out.

Google Lens lets you search what you see. Using a photo, your camera or almost any image, Lens helps you discover visually similar images and related content, gathering results from all over the internet.

All you need to do is: On your phone, open the Google app and in the search bar, tap Google Lens. Point your camera at the flower to identify the plant. Swipe up to learn about the discovery.

On Android, Google Lens is likely already built right in — open the Google App or Google Photos app. Tap Discover or tap the Google Lens icon.

On Apple, Google Lens is part of the Google app — a separate app from using Google on Chrome, Firefox or Safari. Go to the App Store and download/install Google as a unique app if you haven’t already done so.

When you open the Google App, you’ll see a screen like this with the Lens icon. It’s your window to discovery!

Last week, I went for a long walk and checked out a lot of the volunteer trees and plants along the rural roadway. Sometimes I wanted to verify an item I thought I already knew, but more often I wanted to determine the name of a common but name-unknown item. Google Lens scored on both fronts. Now if only I could remember all of those names!

If you have a bug infestation, use Google Lens to identify the bug if you can get it to sit still long enough!

There’s plenty more you can do with Google Lens, too, including pulling the contact information from business cards, identifying unusual foods and almost anything else. It can also translate words on the screen into other languages, and read them back to you.

The ability of the app to actually CORRECTLY identify plants and bugs is pretty decent, and will get better over time. It helps to allow Google to use location services, so that it’s not searching through the entire rain forest to determine the name of the plant in your neighbourhood. You can also allow Lens access to your photos, so that you can identify items you’ve already taken pictures of.

Best of all, it’s free and will always be free. Try it!

The Joy of Sharing our Gardens

Reflections after a Garden Tour

by Emma Murphy, Master Gardener

It’s been a tough few years for all of us because of COVID-19, but I had time to reflect this weekend on why it’s been hard for me as a gardener. While it’s been wonderful to have our gardens as an oasis and source of comfort during the pandemic, I realized that other than a few close friends, no one had seen all the work (and the results) that my husband Grant and I had achieved over that time.

So it was with great anticipation that we looked forward to our Lakefield garden being featured on a garden tour organized as a fundraiser to celebrate 60 years of the Lakefield Horticultural Society.

While we spent a few very crazy days trying to put the final touches on our garden (my husband decided he would build a beautiful pergola [awesome] a week before the event [not so awesome] so plants had to be moved into pots and then back into the beds just a few days before) — sorry I digress — everything was perfect on the day — the weather was spectacular, we placed the last bits of mulch to cover a few empty patches and we looked forward to welcoming our guests.

The new pergola.

As the first people arrived (I think our first visitor was a man on a bicycle!) I began to realize how much I had missed the joy of sharing our gardens with others. And as the day progressed, it was wonderful to hear other people’s perceptions — for some it was inspiring, for some a bit overwhelming (we have a 3/4 acre property in a small village), for some they loved that we had plants they had never seen before (not your typical garden). Everyone seemed to leave with a smile on their face, which made our day.

Grant created numerous raised beds over the past few years — at my request — and we’ve had great success with them. We also purchased a “COVID present” for ourselves — a long wished-for greenhouse to extend our gardening season, and it’s been put to good use.

We’ve spent time over the past few years planting more native plants as I learn more about the benefits of creating habitat as well as having an aesthetically pleasing garden. Hey, it’s not all about me!! Doug Tallamy’s book is a great start to understanding the benefits we can provide in our humble gardens to the greater ecosystem.

There is definitely a balance — we’re aiming for a 50/50 balance of native/non-native — because I love my daylilies and peonies and don’t want to give them up (they give me pleasure), but I also love the hundreds of pollinators (bees, butterflies, wasps etc.) that flock to my Common Boneset (Eupatorium perfoliatum), Pearly Everlasting (Anaphalis margaritacea), Cup Plant (Silphium perfoliatum), and Cardinal Flower (Lobelia cardinalis) because I am choosing to plant native plants.

Boneset (white) and Cardinal Flower (red)

Last winter I grew some native (and non-native) plants using the Winter Sowing technique (because most native plant seed requires winter/cold stratification) and it was a great success (with some lessons learned – but that’s another blog).

Grant set up a Plant Sale area for the garden tour and people were able to buy plants that they saw in the garden (although alas, I did not take any cuttings on my amazing orange Butterfly Weed – a type of milkweed – which really caught everyone’s attention).

The Plant Sale area

Over the day I saw many gardening friends I hadn’t seen in several years, and made all sorts of new friends. It felt like my community was coming together — like we were reconnecting after a long time apart in a beautiful place. And I realized that gardening is both a solitary and a very social activity. We even got featured in the local newspaper.

We raised funds to support our local horticultural society, we got back to feeling ‘a bit normal’, and most importantly we got to reconnect with people over a common passion — the love of gardening.

I hope that all of you will find opportunities to reconnect with people this summer and share your gardens and plants and trade stories about attracting pollinators etc. with others. It’s a feeling like no other. #happygardening

Our lovely rudbeckia and greenhouse in the background.

Native Shrubs

By Cheryl Harrison, Master Gardener

In the spirit of adding more native plants to my garden in order to help support diversity, native pollinators and birds, I recently purchased a New Jersey Tea shrub.  Of course, it is also a new-to-me plant so I could not resist!  This made me start thinking about other native shrubs that I could use in my garden….I already have some of the usual non-natives like hydrangea, lilac, forsythia and a few of the dwarf conifers.  But, much to my surprise, I realized that I also have, in addition to the new-to-me New Jersey Tea (Ceanothus americanus), downy arrowwood (Viburnum rafinesquianum) , dogwood (Cornus species) and ninebark (Physocarpus opulifolius)! 

New Jersey Tea – My newly purchased shrub is just a baby….it is barely 13 cm (5 inches) tall but will grow to be about 1 meter (3 feet) tall.  I will need to protect it from the rabbits, who also inhabit my garden, by caging it with chicken wire.  New Jersey Tea prefers full sun and well drained soil.  It produces small white flowers in oval clusters at the branch tips in spring.  It is hardy to zone 4.  Additional information is available here.

Downy Arrowwood – My arrowwood is blooming right now.  It is covered with clusters of tiny white flowers and many native pollinators.  The flowers will be followed by blue-black berries that the birds love.  Arrowwood prefers poor, well drained soil…..ours is planted at the edge of a gravel walkway. It can take part-sun to shade and is hardy to zone 3.  At maturity, this multi-stemmed shrub will be 1.8-2.4 meters (6-8 feet) tall.  Additional information is available here.

Dogwood – There are a few different species of dogwood native to Ontario including Pagoda dogwood (C. alternifolia), bunchberry (C. canadensis) and Red Osier dogwood (C. sericea).  There are more but this group are hardy to at least zone 5 (Peterborough area).  They vary in height and growing condition requirements.  For more information on dogwood look hereThe Peterborough and Area Master Gardeners also have a fact sheet available on dogwood here .

Ninebark – Ninebark is a great native shrub for your garden.  It adapts to lots of different soil conditions and moisture levels including drought once established.  It is hardy to zone 3, has pretty white blooms in summer and attractive fall foliage.  I must admit that ours is planted in good garden soil and is mulched to minimize weeds and for moisture retention so my ninebark has it pretty good.  This shrub does prefer full sun for best bloom production. The Peterborough and Area Master Gardeners also have a fact sheet available on ninebark here.

Remember that all new plants need to be coddled for their first year in your garden so keep them watered and watch for insects or critters that may cause damage.  For me, that is fairly easy because I am often out in the garden admiring my new plants!

For more native plant choices and other pollinator information, check out Pollinator Partnership Canada under Resources.  June 20-26/2022 is Pollinator Week in Canada.  Why not celebrate by adding one or more native plants to your garden?

Planting Trees

By Sharleen Pratt, Master Gardener

Image Courtesy of pixabay.com

Peter Wohlleben in his well-know book, The Hidden Life of Trees, describes how trees are like families, continually communicating and supporting one another. Trees improve soil and water conservation, moderate climate, increase the wildlife habitat, reduce stress and improve health.

It is imperative we continue to increase the tree canopy in our ever-growing cities.  This became more important after the recent storm that whipped through Southern Ontario and took out so many beautiful trees.

There are many factors to consider when planting a tree and it is easy to make mistakes.  I learned this the hard way this past month when I was able to literally pull a 9-year-old tree out of the ground.  Believe me, I am no incredible hulk!  I made many mistakes when planting that tree; the picture shows it was planted too deep, the roots girdled around the original root ball and by amending the dug hole with compost the tree likely resisted growing roots into the surrounding clay soil.

Image Courtesy of Author

Do your research and purchase a tree that is suitable for your yard conditions: 

  • How much sun and shade you receive each day?
  • What type of soil do you have?  
  • Would you prefer a large tree or one that is smaller and more suitable to an urban setting? 
  • What growing zone do you live in? (Check out this Zone Map if you are unsure)
  • Are you looking for a tree that will attract pollinators?   

I would suggest you consider planting a native tree. Trees that occur naturally in our surrounding area are better adapted to local climate and soil conditions and more resistant to disease. Oak trees are a powerhouse for feeding birds and attracting pollinators and insects, however, they are quite large.  A smaller tree to consider would be an Eastern Redbud or a Fall Witch Hazel.

Here is an article from Landscape Ontario with suggested native trees to consider.

HOLE DEPTH

In well-drained soils, the planting hole width should be two to three times the diameter of the root ball and only as deep as the root ball.  Widening the planting hole produces a hole with a greater volume of loose cultivated soil that allows rapid root growth.  This way roots gain access to a greater volume of loosened soil.  Do not plant the tree’s root flare below the ground.  The root flare should be within the top 5 cm of the soil surface.  Use a brush to find the top of the root flare which is where the structural roots begin.

SOIL AMENDMENT

Remove any grass roots, weeds, rocks or other debris from the planting hole. It used to be believed that you should fill the hole with an organic amendment such as compost, however, recent research has found that this doesn’t improve root development or tree growth and can sometimes be detrimental to tree performance and survival.  It is best to backfill in layers and lightly tamp and water to eliminate air pockets.  Additions of mulch and compost can be surface applied in future years to supplied much needed nutrients.

CREATING A BERM

It is wise to build a 10 cm high berm of soil extending 15 to 20 cm around the periphery of the root ball.  It should be firmed and is intended to keep water from flowing away.

MULCH

Apply mulch such as leaf litter or untreated wood chips evenly at the base of the tree.  It will help to reduce evaporation and suppress weeds.  Be sure to pull the mulch about 15 cm away from the base of the trunk.  The depth should be between 5 to 10 cm. I often see trees planted with mulch piled like a volcano.  This does not allow the water to penetrate to the roots and can also cause damage and disease to the trunk of the tree.

STABILIZATION

Only stake the tree if the roots will not support its height or if it is exposed to high winds. If a tree must be staked, place stakes no higher than 1/3 the height of the tree. Stake the tree loosely so it can move naturally in the wind. This movement will help to increase the tree’s stability.  The staking material should not constrict or rub against the bark of your plant. Remove stakes after roots have established, no longer than one growing season.

LASTLY

Remove all plant identification tags and any trunk protection or packaging material.

Supplemental watering is recommended the first 2-years after planting your tree. A sprinkle with the hose for a couple of minutes does more damage than good as this does not provide enough water to penetrate deep into the soil.  Newly planted trees must be watered regularly until frost.  Also, if water is pooling around the tree, cut back on the watering.

Do not be tempted to add additional fertilizer at this point.  Mineral imbalances can occur and cause more vegetative growth than root growth.

Do not prune the tree beyond removing any dead, diseased or damaged branches.

For further information, check out this Tree Planting Guide from Landscape Ontario.

Winter Browning of Conifers

By Laura Gardner, Master Gardener in Training

This spring as I walk around my neighbourhood, I have noticed quite a few evergreen conifers with brown needles. The species that are commonly affected are mainly the dwarf and ornamental varieties such as Picea glauca ‘Conica’ (Dwarf Alberta Spruce), Thuja occidentalis ‘Smargd’ (Emerald Cedar), and Taxus spp. (Yew). Some of the more robust and resistant conifers are the parent species such as Thuja occidentalis (Eastern White Cedar).

Some Causes[i]

  1. Inadequate moisture
  2. Inadequate protection from sun and wind
  3. Rapid freezing/thawing
  4. Salt spray damage
  5. Root damage at transplant
  6. Late season pruning and fertilization
  7. Late fall transplant
  8. Genetic maladaptation

Cultural Practices for Recovery and Future Maintenance

Depending on the extent of the damage, these shrubs may recover and produce new growth. This process can be encouraged by additional watering and the addition of mulch. Shrubs should be well-hydrated up until freezing in the fall to prepare them for moisture loss in the following winter. Mulching helps protect shallow roots from drying out, can help limit frost-heaving, and moderates the temperature of the soil.

Prior to winter, consider adding some protection such as a burlap screen with stakes for plantings on the south and/or west side where it is sunny or windy or near driveways and walkways that are salted. Burlap can be wrapped around shrubs but should be kept loose so that moisture is not trapped. The advantage to a screen is that the area remains open to air and light. Salt, sun, and wind can draw out moisture from the needles and because the ground is frozen, the roots are unable to draw in replacement moisture. Planting these types of shrubs on the north and east sides, in less open areas, and away from driveways can minimize damage.

Shrubs that have been dug from the nursery field and then have been repotted for sale may be subject to some root damage/loss. This can be more problematic when transplanting late in the fall as there is limited time for root re-development. In addition, the ability of the roots to draw in moisture before freeze-up can be compromised. Refrain from pruning and fertilizing late in the summer as this can encourage a flush of late new growth—tender growth that is more susceptible to winter damage.

Conifers that are exhibiting winter browning:

Is Supportive Care Enough?

Perhaps—it is required in the first few years after transplant and probably they will continue to require extra support. However, some dwarf and ornamental conifer cultivars are simply not genetically adapted to thrive in this region. This is because they have originated from areas of more moderate climate and hardiness zones. When considering trees and shrubs, while some species are more adaptable than others, it is preferable that stock be grown locally and be from local cuttings and seed. Forest Gene Conservation Association notes that “bringing material in from dissimilar areas often results in low survival from heat stress or winterkill, frost damage, reduced growth rates, and increased insect and disease problems.”[ii] While climate change is indeed allowing us to push the envelope a little and plant some species from the next hardiness zone, and there are assisted migration[iii] programs for species, there can be a risk in transplanting certain plants from further afield. Plants are genetically adapted to follow a particular timed growth cycle. For example, a study of Quercus rubra (Red Oak) found that a specimen grown in Algonquin Park that was transplanted in the Niagara region stopped growing before the end of the growing season. It was genetically adapted to a growing season of 185 days but the growing season in Niagara is around 230 days. Another specimen grown in Niagara that was transplanted in Algonquin Park was genetically adapted to continue growing past the end of the growing season there and as a result suffered frost damage and browning. It would be weakened and be more prone to damage from disease and insects.[iv]

Another study of Picea glauca (White Spruce) in Alberta found that cold hardiness was determined to be the trait with the strongest genetic variation. Seed from plants originating from Ontario had high growth but a poor survival rate. Because they were accustomed to longer growth periods, there were more vulnerable to early damaging frosts. The plants with the highest survival and growth rates were grown from local stock.[v]

Before purchasing, determine your garden’s site conditions: soil, moisture, drainage, sunlight, wind, climate, and whether the trees or shrubs you are considering can adapt readily to the conditions. Climate change also needs to be considered as we experience increased drought and higher temperatures. Determine their origin. Ask the vendor where they were grown. If they originated from an area with very different conditions, consider giving them a pass. Realize that “if a tree is not genetically adapted to your site conditions, no amount of care will help it grow as vigorously as one from the appropriate source.”[vi]

Keep in mind the gardening adage, “the right plant for the right space.”


[i] Winter Burn. University of Wisconsin Garden Fact Sheets. Online: https://hort.extension.wisc.edu/files/2015/01/Winter-Burn.pdf

[ii] Seed Source Matters. Forest Gene Conservation Association. Online: https://fgca.net/2016/12/seed-source-matters/

[iii] Assisted Migration. Forest Gene Conservation Association. Online: https://fgca.net/climate-change/assisted-migration/

[iv] How Far Should the Seed Fall from the Tree? It’s a Question of Respecting Diversity: Genetic and Environmental. Online: https://ontariosnaturalselections.org

[v] Sebastian-Azcona, Jaime, et al. Adaptations of White Spruce to Climate: Strong Intraspecific Differences in Cold Hardiness Linked to Survival. Ecology and Evolution, vol. 8, no. 3, 2018. Online: http://dx.doi.org/10.1002/ece3.3796.

[vi] When Planting Trees. Forest Gene Conservation Association. Online: https://fgca.net/forest-gene-convservation/when-planting-trees/

Why Do We Garden?

by Emma Murphy, Master Gardener

“To plant a garden is to believe in tomorrow.” Audrey Hepburn

If you’re like me, you love to garden. Time in my garden provides me with joy on so many levels — emotional, physical, social, creative — and connects me with the outdoors and the environment. And while the COVID-19 pandemic has turned our lives upside down, one of the silver linings is that we’ve seen a renewed interest in gardening and its benefits, whether you’re working in a large garden or a few containers on your balcony. So I thought I would explore some of the top reasons I think we garden.

Physical and Emotional Health

Gardening is physical. As a low to medium impact exercise that requires both strength and stretching, you’ll see increased muscle strength and cardiovascular fitness over time, as well as improved sleep and diet (if you grow your own produce). On the emotional side, gardening reduces stress, anxiety, and depression and improves self esteem.

It’s good for the mind — gardening calms me down and helps me be more patient with myself and those I interact with on a daily basis. It gives me time to contemplate as I go about my tasks, up to my elbows in soil. Even weeding is cathartic, pulling out those little terrors by the root!

Just visiting gardens helps to calm the mind, bringing a sense of contentment and tranquility from looking at beautiful landscapes, flowers, or just colour and texture.

Building Relationships

While gardening can be a solo activity (some of my favourite moments are just by myself in my green oasis), it’s also a fabulous way to connect with people, whether they be family or strangers!

Teaching people how to nurture a living thing and to be responsible for a little bit of the environment is a lesson and gift we can share with others. Gardening knowledge is shared through generations — I love hearing about plants handed down from grandparents, or children working with their parents to grow seeds for the first time. It’s a great way to pass on critical life lessons — about patience as plants and vegetables grow, responsibility as they look after their care, and loss when flowers die at the end of a season.

Beyond family, gardening helps us connect with the broader community. Whether you plant too many tomatoes or zucchinis and end up giving them away to neighbours, or participate in a community garden plot, gardening can be a very social activity and a chance to learn from, and share your bounty, with others.

Learning Life Values

Gardening teaches you important life values like patience, determination, caring, and hard work. It also makes you very humble as you realize that there is always something new to learn. You need to observe the seasons and the weather, and this puts you in contact with the natural world. I love that I can get dirty and do this very physical activity, working with seeds and plants and seeing growth in all I do.

Growing Your Own Food

Gardening provides benefits for your wallet, your nutrition, and reduces your environmental footprint. By growing your own food (either from seeds or small plants), your food is automatically more sustainable simply because you are doing it onsite or in a community garden. If you control the ‘inputs’ and do it well, you can save a lot of money.

But ultimately there is nothing more rewarding than planting and maintaining your own vegetable garden and harvesting (and sharing) your results. And we all know how much better homegrown produce tastes versus conventional produce at the grocery store. If you have too much produce, then you can just share the love with others!

Connecting With Nature

I think this is one of the best reasons why people have a garden — the sunshine on your face, hands in the dirt, and feeling connected to nature. The garden is so much more than just plants and flowers — it’s the birds, the bugs, the bees, the spiders, the snakes and all the small mammals. I feel like I am establishing a little ecosystem in my own garden and that I am trying to give back for all the benefits that I receive.

Working in the garden also gives you that sense of wonder, accomplishment, and reward. To grow plants is to give life. It keeps you busy but reminds you to be one with the earth. To see the results of something growing from seed to six feet tall is just incredible.

Exploring Creativity

I find gardening to be an incredibly creative activity. Finding the right plant for the right spot, mixing colours, and making sure there is interest for every season — these are real challenges. I’ve spent much of the past few years learning about new plants to consider in my garden, especially natives.

Helping The Environment

Finally, gardening is so important for our planet. Even though we create our gardens (so they are human made) they do represent natural environments, with trees and shrubs and plants that are all taking in carbon and releasing oxygen. The plant roots stabilize the soil and filter water, and the plants themselves support our pollinators.

We live in a symbiotic relationship with our gardens. We give back by planting and maintaining them, but we receive so much more from them than we give.

Why do you garden?