Category Archives: Shrubs & Trees

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?

beware! Think twice about these plants for your garden

by Rachel Burrows, Master Gardener

Plants are unable to hide or run away when faced with danger such as being eaten by a hungry rabbit. However some plants are toxic and can cause anything from mild discomfort to fatal consequences. Many of them are lovely to look at but it is wise to know which are poisonous especially if you have young children or pets.

Castor bean plant

Castor Bean Plant (Ricinus communis)

A friend phoned me and said that she had a fabulous plant with very unusual seed heads and would I like to take a look at it as she didn’t know what it was. Castor bean plants contain ricin, one of the most toxic substances known. The ricin is in the seeds which are covered with a prickly coating and are pretty shade of dark red. If the seed is swallowed whole without damaging the seed coat it will likely pass through the digestive system harmlessly. However, if it is chewed and swallowed the ricin will be absorbed within minutes and is usually fatal. One seed is enough for a deadly dose for a child and about four for an adult. My friend was very surprised and agreed to dig the plant put of her garden and dispose of it safely. These plants are often grown for their ornamental properties as they are tall and a lovely colour.

Yew

Yews (Taxus)

Again, another popular plant for hedges and often seen in gardens. The entire shrub is poisonous except for the red flesh of the berries. The oval, black seeds within the berries are highly toxic and can be fatal within a few hours of eating as few as 3 seeds. The toxin in yews is taxine which is a cardiac suppressant. I grew up on a farm and we all knew not to have yews in fields with livestock.

Rhododendron

Rhododendron

Not so hardy and a little harder to grow in this area but very common further south and in parts of England. All parts of the rhododendron are poisonous, even honey produced form the shrubs is poisonous.

Mountain laurel flower

Mountain Laurel (Kalmia latifolia)

This shrub is a close relative to Mountain Laurel and all the green parts, twigs, blooms and pollen are toxic. It’s blooms are gorgeous but beware!

Lily of the Valley

Lily of the Valley (Convalliaria majalis)

Lily of the Valley is valued for its lovely perfume and as a ground cover, although some people see it as a menace as it does spread quickly. The entire plant is poisonous and causes the heart’s contractions to intensify.

Monkshood

Monkshood (Aconitum)

This is a stunning, tall perennial which blooms late in the season with striking purple flowers. All parts of the plant especially the roots and seeds are extremely poisonous. Eating as little as 1 gram may cause death. Even the sap can cause fingers to become numb.

Delphinium

Delphinium

Another lovely and showy perennial, but all parts of the plant are poisonous, especially the seeds. Death can be caused in as little as 6 hours.

Foxglove

Foxglove (Digitalis purpurea)

Another commonly grown plant that produces the well known heart medication. However, the whole plant is poisonous and the toxin is deadly in high doses.

There are several other poisonous plants that you might want to think twice about before bringing them into your garden. Be aware of their deadly potential especially if you have young children or pets. By all means grow them if you love them, just be careful.

Did you know? There’s a garden in England dedicated to poisonous plants? Take a tour – virtually..

For further information and pictures of other poisonous garden, wild and house plants check out these websites

Ontario Poison Centre – Plants

Good Housekeeping List of Poisonous Plants Around the Home

Landscape Ontario – List of Poisonous Plants


The Intricate Nature of Trees

By Laura Gardner, Master Gardener in Training

I first became aware of Suzanne Simard and her forestry research through an online TED talk that I watched as part of an arboriculture course that I had taken. The talk was engaging, enlightening, and inspiring. In it she spoke about the interconnectedness of and the collaborative, communicative, and nurturing nature of different tree species and how networks of mycorrhizal fungi serve as connectors between them. These mycorrhizal fungi, located within a tree’s roots, enable the transfer of nutrients and help them to thrive.

When I saw a year later that she was to publish a book as a follow-up, I jumped at the chance to read it. Finding the Mother Tree: Discovering the Wisdom of the Forest (Knopf, 2021) not only covers her scientific research but it is also part memoir in that the author weaves her own personal life story within the narrative. We hear how at an early age she had become in tune with and respectful of the forests, influenced by her grandfather, who had practiced logging in a sustainable manner. She would go on to work for logging companies as well as conduct research for the British Columbia Forest Service, trying to determine why certain conifer species grown for harvesting were not thriving and whether eliminating certain tree species would contribute to a more productive end result or be a hindrance.

Simard was skeptical that this long-standing “free to grow” policy was sound practice for the long-term survival of the forests. Her eventual research findings would conflict and effecting change would prove to be difficult and was met with resistance. The view that trees were in strict competition with each other and that best results would be derived though eliminating “unproductive” or “devalued” trees such as Alder and Birch from the plantations could no longer be supported. It would not be easy to convince policy writers to change course and see the more collaborative, symbiotic nature between the different species and the importance of mycorrhizae – that eliminating certain deciduous species actually made the conifers more vulnerable to Armillaria root disease or insect pests such as the Mountain Pine Beetle. Simard would also show that the sharing of resources extended not only between parent and offspring trees, but also between genetically unrelated trees.

Simard demonstrates the disadvantages of developing monoculture environments in the forestry industry but her research should also give much food for thought for those working in urban forestry, landscaping, agriculture, or even at the individual homeowner level. The common
practice of planting the same kinds of species or the isolated planting of an individual species should be reconsidered more widely. These practices lead to less ecological diversity and may reduce the potential for a planted tree’s optimum growth. Perhaps we should consider planting certain species of trees together or in close proximity in order to foster the underground mycorrhizal networks that help strengthen and support them. Perhaps for planting consideration is an alder and a pine or a fir and a birch combination?

Reading this book will change the way you think about trees and you will want to continue to follow Simard’s research. Learn more about the Mother Tree Project.

Pruning Tips for Spring Flowering Shrubs

By Lois Scott, Master Gardener

Spring finally arrived and is now quickly passing, as are the blossoms on spring blooming shrubs such as Forsythia, Lilac and Bridlewreath Spiraea.  Once these shrubs are finished blooming, we can ensure that next year’s blossoms will be abundant by pruning them effectively.

These shrubs flower best on the wood that grew the previous summer and they benefit from some yearly pruning done right after blooming and before new growth begins. The general idea is to prune out some of the oldest wood each year so that your shrub is renewed over time and does not become overgrown and underperforming.  Along with the following tips you should always prune any material that is dead, diseased or dying when you find it.

Lee Reich, the author of “The Pruning Book” recommends the following pruning process.

  • Cut to within 1 ft (or less) of the ground some of the oldest stems.
  • To keep your clump to a desired size, selectively cut some of the oldest stems from around the edge of your clump.
  • If desired shorten some of the remaining older stems.  This will keep your shrub short enough that blossoms will be more accessible.
  • If you have just planted a new shrub this spring, the recommendation is not to do any pruning while plants are young.  Just mulch, water and weed your shrub, pruning only material that is dead, diseased or damaged.  Pruning stimulates growth and for a young shrub it is important for the energy to go towards root growth.
  • Use loppers and hand pruners rather than hedge trimmers.

I agree with Lee when he says “it’s best to use your pruning tools to coax a bush along in the direction of its natural inclinations” rather than trying to contain naturally arching shrubs into ‘balls’.  Planting shrubs in locations where they have room to grow into their natural shape is preferable to me, however pruning can be a creative pursuit so each to their own!

Resources

It is Time to Prune Lilac, Forsythia and Other Early Spring Flowering Shrubs

Penn State Extension: A Prime Time to Prune!

Joys of Nature and Spring Garden Tasks

By Sharleen Pratt, Master Gardener

April 22nd was Earth Day.  It is a time for reflection on what we can do to help develop a new approach to conservation and it can all start in our own yard. As we experience what we all hope will be our last full shutdown, we need to remain optimistic in the growing interest in gardening with natives and the number of younger people who are learning to grow their own vegetables.  Douglas Tallamy, author of Nature’s Best Hope, writes that as homeowners, we need to “turn our yards into conservation corridors that provide wildlife habitats”.

Spring is a time of renewal.  To help us get through the stressful days of this lockdown, a walk outdoors will help you experience the joys of nature and all it has to offer! 

I have created two lists.  The first is ‘Joys of Nature’ that you will encounter this time of year.  The second is ‘Garden Tasks’ to tackle over the next few weeks.

JOYS OF NATURE

Hepatica image compliments of Joan Harding, Peterborough MG
  • My garden makes me smile this time of year with all the blooming Daffodils (Narcissus), Hyacinths, Hellebores and even Lungwort (Pulmonaria officinalis). 
  • Local ponds are alive with the sounds of the spring peepers and the chorus frogs.  If you take a walk and come across a wetland, you will be amazed at the sound.
  • Many of the migrating birds and waterfowl have returned.  My feeders are being well used by the yellow finches, grackles, house finches and mourning doves.  If you enjoy the hummingbirds, don’t forget to get your feeders out now.  They will soon be back!
  • A walk through the woods will reveal the beauty of the spring ephemerals.  Ephemerals are short-lived spring flowers that take advantage of the sunshine before the trees get their leaves.  I have seen bloodroot, hepatica, coltsfoot and the beginnings of the trilliums and the dog-toothed violets.
  • If you are out digging in your garden, don’t be surprised if a robin will follow you around in the hopes you might throw him a much sought-after worm.  Robins are already nesting so the female is likely to be at the nest site.
  • Watch for early butterflies such as the Mourning Cloaks, Eastern Comma and the Spring Azure.
  • In early May, you should begin to see the white blossoms of serviceberries and the beginnings of the lilacs and the cherry blossoms.

Get outdoors, take a deep breath and walk slowly through a local park or wooded area and enjoy many of the items mentioned above.  Do it now before the return of the blackflies and mosquitoes!!

If you are interested in a sample of simple nature events in the Kawarthas, Drew Monkman, a retired teacher and well known environmentalist and advocate for climate control, has written this monthly almanac: https://www.drewmonkman.com/sample-page/monthly-almanacs/

SPRING GARDEN TASKS

Author’s Spring Garden… Hyacinths, Bloodroot and Daffodils
  • Only rake your lawn if walking on it leaves NO footprint.  The time to overseed your lawn is generally when the lilacs are in bloom.
  • Now is the time to top dress a generous amount of compost and other organic material into your garden beds.  Let the earthworms do the work.  I do not suggest that you rototill your garden as this disturbs the beneficial life in the soil.  Bacteria, mycorrhiza and insects are damaged, sometimes beyond repair, with rototilling.
  • Prune overgrown vines and shrubs such as some hydrangea and some of the clematis; basically all the shrubs and vines that do not bloom in spring.  Do not prune lilacs as they bloom on last year’s growth.
  • Gradually remove protection on rose bushes and prune down to a swollen bud.  Remove dead, diseased and crossing branches.
  • If you haven’t already, now is the time to sow frost tolerant veggies such as peas, carrots, spinach, lettuce, beets, kale and radishes directly into the garden.
  • Divide and transplant perennials as growth resumes.
  • Now is a good time to think about planting shrubs and trees.  Maybe you would like to replace an old shrub with something native, such as Black chokeberry (Aronia melanocarpa), Eastern snowberry (Symphoricarpos albus) or Gray dogwood (Cornus racemosa)
  • Be sure to have your rain barrels set-up and ready to collect that wonderful spring rain.
  • Keep your bird baths filled and cleaned.
  • If you have been growing tomatoes, peppers, cucumbers and annual flowers indoors, early May is the time to begin to harden off those young seedlings.
  • The soil is still quite soft, so now is a good time to edge your garden beds as well as start to pull all those weeds that seem to survive no matter what the weather.

    Get out in your gardens, enjoy the warmer temperatures and don’t forget to get your knees dirty!

Let Us Praise Famous Oaks

By Laura Gardner, Master Gardener in Training

Ed: This post was released in error on March 22. Apologies if you’ve already read it — perhaps you can glean something from it upon second reading as well?

Quercus macrocarpa (bur oak) in Centennial Park, Peterborough, ON.

There are a pair of Quercus macrocarpa (bur oak) trees in a park near my house in Peterborough and I often look at them in awe. I estimate that these trees are between 100 and 150 years old. What is amazing is that they could live another 150 years. If they receive enough sunlight and moisture and their roots are undisturbed, this lifespan is possible. Sadly, most trees planted in cities are not long-lived due to stresses like heat, drought, road salt, compacted soil and interference by sewer or other utility lines. For these reasons, backyards tend to be the better locations for trees in urban environments. If you are planning to plant a tree on your property this year, Douglas W. Tallamy’s latest book, The Nature of Oaks: the Rich Ecology of Our Most Essential Native Trees, published by Timber Press, will make you seriously consider an oak tree.

Tallamy, an entomologist who researches the relationships between insects and plants, is well known for his other books that seek to change the way we garden by encouraging us to incorporate more native plants. His latest book honours the oak tree and provides a month-to-month chronicle of the life of one on his property.  While small at 200 pages, the book has many interesting and informative anecdotes about the types of insects, birds, mammals, fungi, and micro-organisms that live in, on, and around these trees. Tallamy aims to instill in us an interest in these great trees and to recognize their important role within the food web.

What makes oak trees so special? In addition to moderating the climate, reducing pollution, producing oxygen, and storing carbon from the atmosphere, they have an enormous impact on the lives of other species. Within our ecosystem, oaks support more life than any other North American tree genus (p. 12) and they are considered a “keystone species.” A “keystone species” is one that produces food that supports a broad range of life forms. Over the course of its lifetime, an oak can produce over 3,000,000 acorns. Other trees such as birch, cherry, hickory, pine, maple, and willow are also “keystone” species (p. 39) but they are not as supportive as oaks. In his research, Tallamy measured the degree of this support by counting the number of moth and butterfly species that live, feed, and reproduce on different trees. The Lepidoptera Index places oaks at the top of the list at 532 species of moths and butterflies. One of the reasons as to why they support so many species is because they grow in a wide range of ecological zones (p. 41). Most species near the bottom of the list are non-native trees and shrubs. Most of our native insects and animals have not fully adapted or evolved to non-native plants or are only adapted to a small number of plants—referred to as host plant specialization (p. 37). Certain birds, like the black-capped chickadee need between 6,000 and 9,000 caterpillars to raise one clutch of young. Filling bird feeders with seed can be beneficial for them, but planting trees are necessary as up to 50% of their diet consists of insects (p. 34).

There are a number of unique and fascinating attributes of oaks that are explored in the book. Masting is a survival adaptation that occurs periodically in oaks where they produce many acorns. Since animals cannot eat them all, this allows more trees to grow (p. 18). Masting occurs on different cycles for both white and red oaks and this ensures food is consistently available for animals (p. 120). Many oaks retain their dead leaves through the fall and winter. Marcescence is thought to be a defence mechanism that deters animals from eating the tender buds (pp. 27-28).  Concerning acorn production, as an oak tree has both male and female flowers, a few can self-pollinate and grow acorns. However, for optimum production, an oak tree must be planted with another of its own species or be in close proximity to another of its own species for pollination (by wind) to occur (from either the “red oak” or the “white oak” group).

Marcescent Quercus rubra (northern red oak) along Heritage Trail, Peterborough, ON

Tallamy also provides us with some tree planting advice and seeks to dispel some of the myths around planting oaks. His first choice would be for us to plant an acorn in the fall but the next best choice would be to plant a bareroot whip in the spring. A bareroot whip is a pruned dormant tree that is only a few feet tall. It should be planted in the spring so it can break its dormancy naturally. Overall, he recommends purchasing the youngest tree available because it will have a better chance of survival than a larger tree. Larger trees often have damaged roots at planting and have a 50% chance of dying in the first few years after transplant. (p. 47)

While some oak species grow to great heights and widths, they do grow relatively slowly, and most people will not live to see their tree at its peak. Some may be concerned about its root system, but they extend deeply into the ground and tend not to interfere with driveways or sidewalks like some other species. Tallamy recommends planting two or three trees spaced 10 feet apart—in a grove. This may seem too close, but it is true to their nature in the wild. The trees’ roots will also bind together and the resulting strength of them will be able to withstand extreme weather and lessen the chances of damaging property.

For those with smaller lots, it may not be practical to plant more than one oak, let alone a larger species like Quercus alba (white oak) or Quercus macrocarpa (bur oak). There are several smaller oak species that may suit. Of these, two are native to the Carolinian zone of Southwestern Ontario: Quercus prinoides (dwarf chinquapin oak) and Quercus ilicifolia (bear oak) and one from the US Northeast: Quercus marilandica (blackJack oak). While the soils of the Carolinian zone are drier and sandier, these trees can be adaptable to other soil conditions. Nutcracker Nursery in Maskinonge, Quebec specializes in growing these hard-to-find oaks and they ship bareroot stock. The stock is grown in cooler zone 4B and in clay-loam soils. Peterborough GreenUp advises that while it is preferable that trees be selected from within their native eco-zone, climate change is making it more possible for us to consider some species from outside. Selecting a site that is shielded from winter winds is recommended.

Since an oak is a shade tree, there may be concerns about what can be grown beneath them but there are many plants that are suitable for the understory. Tallamy makes recommendations that are more suited to US states but I will suggest some possible plants suited to our area: Asarum canadense (wild ginger), Polygonatum biflorum (smooth solomon’s seal), Aquilegia canadensis (eastern red columbine), Ceanothus americanus (New Jersey tea), and Amelanchier alnifolia (Saskatoon serviceberry), just to name a few.

This little book is not only fascinating to read, it is inspiring. When the declining non-native Acer platanoides (Norway maple) is eventually removed from my yard, I am going to see about replacing it with a native oak “keystone species.”

Other Resources

Nutcracker Nursery and Tree Farm

Peterborough GreenUp. Choosing the Right Tree in Peterborough, Ontario

Smithsonian’s National Zoo and Conservation Biology Institute. Lepidoptera Index, June 2017

Tree Atlas of Ontario

Winter Bird Treats

By Lois Scott, Master Gardener

I have been fortunate this winter to have the ability and opportunity to carry on with regular, ‘socially distanced’ walks in my neighbourhood and to be able to enjoy the winter interest provided by nature. 

On several walks I was quite excited to see small flocks of Pine Grosbeaks and Cedar Waxwings feeding on ornamental crabapple trees (Malus species) in two neighbouring gardens that I pass by.  For me it was a special treat to see Pine Grosbeaks, as they are a somewhat irregular winter visitor to the Kawarthas.  Their breeding range is in the boreal forest and, according to Drew Monkman, if there is food they stay put. If not they travel south where you may see them on feeders or fruit trees, such as crabapples.  

Crabapples, typically planted for their flowers, produce colourful fruit that is not only attractive in winter but a potential source of food for birds.  In choosing a variety to plant, Landscape Ontario recommends considering resistance to disease and insects, and fruit persistence, which is important for feeding the birds as the crabapples need to stay on the tree. Another noteworthy fact is that birds can be picky eaters and in their estimation apparently not all crabapples are created equal.  For example they like ‘Prairiefire’ whereas they do not like ‘Adams’, ‘Donald Wyman’ or ‘Red Jewel’.  Who knew!  I don’t know what the varieties are of the two different trees I saw birds in but the tree in the first photograph shows the tree fairly well stripped of fruit. In the second photo there is still plenty of fruit that they have not come back to finish. 

Crabapple trees in the author’s neighbourhood

There are other excellent choices of native trees and shrubs that can provide winter food sources for birds.  The hackberry (Celtis occidentalis), a shade tree that works well in ‘difficult’ urban areas, hawthorns (Crataegus species), highbush cranberry (Viburnum trilobum), and red chokeberry (Aronia arbutifolia) are a few good choices. 

For a more comprehensive list of crabapple varieties and other native species to feed the birds in winter please check out the following links.

For more general information on attracting birds to your garden please check out Master Gardener Judy Bernard’s excellent posts on our Peterborough Master Gardeners website.

Winter, when a gardener’s thoughts turn to Spring

By Emma Murphy, Master Gardener

So now it’s wintertime. Our plants are sleeping quietly beneath a bed of wonderful white snow, and although we hibernate and rest to a degree, a gardener’s thoughts turn to springtime. I’m exploring some new ideas for my gardens for next spring, and thought I would share them with you.

Credit: Joseph Tychonievich; cartoon from https://www.facebook.com/FineGardeningMagazine/photos

No I didn’t get a greenhouse for Christmas…yet.

RAISED BEDS FOR GARDENING

But I do have a wonderful husband who knows how to make his wife – the Master Gardener – a happy person. His Christmas 2020 gift to me was to create some raised beds so we will be doing that this spring. I have been wanting to do raised beds for a few years since seeing Tara Nolan do a presentation at the Peterborough Garden Show, and I guess dropping those significant hints finally worked 😉

So we did a little research. Have you been thinking of creating raised beds for either vegetable or other gardening? They are great to extend the gardening season, be able to control soil quality, provide accessibility for older gardeners or those with disabilities, create a garden for special purposes (youngsters or horticultural therapy), increase yields, reduce weeds, and keep critters at bay. They also work well for condos and rooftops in our urban centres. Here’s some great sites I found for those interested in the idea.

One of my favourite gardeners with a similar climate to mine in Central Ontario – Erin Schanen in Southeastern Wisconsin (zone 5) – The Impatient Gardener. She has several good articles on growing in raised beds, from layout through to construction.

Tara Nolan’s book Raised Bed Revolution emerged at a time when this idea was gaining a lot of traction, and it’s an excellent source of information on size requirements for constructing raised beds, height suggestions, types of materials you can use, and creative tips for fitting the maximum garden capacity into small spaces—including vertical gardening. The Toronto Botanical Garden also wrote a great review. We also have a copy of Mel Bartholomew’s Square Foot Gardening, which focuses on growing more fresh produce in less space, and is very complementary to the raised bed philosophy.

For some general information on raised beds try here and here.

ORDERING YOUR SEEDS

Maybe it was just the crazy rush (and delay on delivery) for seeds this past spring, but we just ordered our vegetable and flower seeds for the 2021 season. There are lots of seed companies to choose from, but please try to shop from Canadian companies and especially those local to you. Although COVID-19 meant the cancellation of Peterborough’s wonderful Seedy Sunday, the organizers did post a list of all the vendors who would have been there, and it’s a great resource, as is the Seeds of Diversity site.

ESPALIERED FRUIT TREES

Espaliered fruit trees (espalier – to train a tree or shrub to grow flat against a support or wall) have been on my garden wish list for several years, and I missed an opportunity to pick up a mixed apple espalier tree several years ago which I have been kicking myself for ever since. I saw amazing espaliered fruit (English style) in the Victorian Kitchen Garden at Meadow View Gardens (just north of Cobourg) on a Master Gardener tour several years ago, and was entranced (well I’m entranced by owners Julie and Garry Edwards’ entire English-inspired gardens, but that’s another story).  

Although they can be any kind of fruit they are most often apples, and the key to doing it well is understanding how to prune the trees. Garden Therapy has an excellent article on how to grow these edible gardens, in ways that can accommodate both small spaces but be decorative. There are many different shapes that can be done – cordon (branches straight out to the sides), fan (branches fanning up and to the side), candelabra (like a cordon but the branches turn at a right angle to form the shape of a candelabra), lattice (multiple trees with crossing branches), and “Y” shapes. Maybe this is something you can try in your garden as well? The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) has a list of nut and fruit tree nurseries. I know one company I have dealt with is Silver Creek Nurseries in Wellesley, who specialize in fruit trees, and they offer the following advice on their website:

“Spur bearing varieties are recommended (rather than tip bearing), such as Cox’s Orange Pippin, Winesap, Fuji, Belle de Boskoop, Calville Blanc, Sweet 16 and many more. Apple and pears are generally the easiest fruits to train, but other species may be espaliered with varying degrees of difficulty.”

Grow a Little Fruit Tree: Simple Pruning Techniques for Small-Space, Easy-Harvest Fruit Trees is also recommended as a resource (although I haven’t read it).

I’ll be in touch with them once spring rolls around, which should be in 82 days or so (but who’s counting?). Enjoy your winter garden dreaming, and spring will be here soon enough.

Trees for the Understory

by Lois Scott, Master Gardener

This year the overstory (forest canopy) was clearly a showstopper. The beautiful fall colour can certainly outshine the understory that grows beneath, however the understory has its own beauty and this is where the greatest diversity is found. The understory is comprised of the vegetation that grows beneath the canopy including “seedlings and saplings of canopy trees together with specialist understory trees, shrubs and herbs”. https://en.wikipedia.org/wiki/Understory

In our urban landscape a natural understory can be largely missing, particularly in our urban gardens. In my own garden, along with an increasing number of native herbs and shrubs I have included a few native, “specialist” understory trees to increase diversity. They grow well in the shade of neighbouring canopy trees, will all tolerate urban conditions and are worthy substitutes to many for the non-native horticultural varieties.

Blue BeechCarpinus caroliniana  aka American Hornbeam, Ironwood, Musclewood

This tree has a blue tinged bark that is hard and smooth with a sinewy appearance.  It grows up to 8 metres high with a low and spreading habit.  It prefers deep, rich moist soils and will tolerate some flooding.  Although is prefers shade it will tolerate full sun with enough moisture.  Squirrels and birds will eat the seeds and flowers.  The leaves turn a beautiful reddish copper colour in the fall.  Mammals avoid browsing twigs and branches due to their unpalatable taste.

Blue Beech

IronwoodOstrya virginiana aka Hop-Hornbeam

Although the Ironwood tree shares a similar common name to the Blue Beech these are two distinct trees.  The Ironwood grows up to 12 metres with a wide spreading crown and long slender branches.  It is very adaptable and will grow in full sun to full shade.  It prefers well drained to slightly dry soils and is an excellent tree for an urban area.

Ironwood

Pagoda DogwoodCornus alternifolia

The Pagoda Dogwood is a small graceful tree with a flat, layered appearance growing up to 10 metres.  It prefers moist, well drained soil.  It has beautiful white fluffy spring flowers that mature into blue, berry like fruits that are attractive to a wide variety of birds.  It is also a butterfly larval host.

Canadian ServiceberryAmelanchier canadensis 

The Canadian Serviceberry grows up to 8 metres. It bears elongated clusters of white showy flowers in spring followed by red berries that birds devour. It is drought tolerant and will grow in both shade and sun.

https://www.greenup.on.ca/wp-content/uploads/2019/05/2019May15_EcologyParkCatalogueMasterDraft.pdf

https://www.yourleaf.org/blog/jen-vander-vecht/jul-15-2015/seeing-understory-through-trees