Category Archives: Shrubs & Trees

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

Bewitching Witch Hazel

By Lois Scott, Master Gardener in Training

Although the title to this blog may sound overstated, I find my Common Witch Hazel, known botanically as Hamamelis virginiana, to be anything but common. This native, deciduous shrub has a rounded crown with a graceful, vase shaped growth habit and yellow, fragrant flowers that emerge September to October along with yellow fall leaf colour. The flowers are ‘stem hugging’ clusters with four ‘crinkly, strappy, ribbon shaped petals’ that usually emerge while the leaves are still on the tree.

thumbnail_Witch hazel blossoms_3302 2
Witch-Hazel blossoms in the author’s garden

The Common Witch Hazel grows in eastern North America including eastern and southern Ontario and can be found in woodlands, and along forest margins and stream banks.  In the garden it can be used as a shrub, hedge, or as in my case, pruned into a small, multi-stemmed specimen ‘tree’, which suits my small suburban garden.  Growing 15-20 feet high and wide, in full sun to part shade it grows well in average, medium moisture well drained soil.  It is a low maintenance shrub with no serious insect or disease problems and requires only minimal pruning done in spring.  (As with any woody plant pruning out dead, damaged or diseased wood should be done when discovered.) Among its many charms this native shrub has a beautiful winter silhouette, attractive grey bark, attracts birds and is considered tolerant of road salt, deer, erosion and clay soil.  According to the Morton Arboretum, Common Witch Hazels also serve as a host plant for the larvae of the spring azure butterfly.  What’s not to love!

thumbnail_Witchhazel garden_3341-0
Witch-Hazel in the author’s garden

Hamamelis virginiana has an interesting reproductive process.  The flowers are wind or insect pollinated but after pollination fertilization of the ovules is delayed until the following spring with the fruit developing during that growing season.  The fruits are greenish seed capsules that become woody by fall.  These woody seed capsules then split open ‘exploding’ its one to two black seeds up to 30 feet away.  According to the Brooklyn Botanical Garden fruit set is very low.

If you are eager to add this or some other native plant to your garden/property, drop in to Peterborough’s GreenUP Ecology Park for plants and expert advice.

References

Missouri Botanical Garden: Hamamelis virginiana
The Morton Arboretum: Common Witch-Hazel
Brooklyn Botanic Garden: Native Witch-Hazel

What We Want and What Trees Need–Or Which Tree do I Buy?

By Cheryl Harrison, Master Gardener

We plant trees for various reasons. Trees are one of the main contributors to a beautiful landscape. They provide shade and can provide a windbreak. Trees sequester carbon and help to clean the air … some can even help to clean toxins from the soil. They serve as homes, shelters, and food for many birds and other small and large creatures including humans. A stroll through a forest can cool, calm, and inspire us!

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There is a lot to consider in order to choose the right tree for you.

Make a List:

  • Do you want shade, shelter, privacy or just something to fill a spot?
  • Do you want a tree that produces fruit or flowers?
  • Do you prefer leaves (deciduous trees) or needles (coniferous trees)? · Do you want a native tree?  See Ontario Tree Atlas to see which trees are native to your area of Ontario.
  • Think about your budget. Some trees are more costly than others.

Location Considerations:

Stand in your chosen potential tree planting location and look around.

  • How close is your home and other buildings including the neighbour’s?
  • Are there any overhead wires that the tree’s branches will interfere with as it matures? Will the mature tree block window views?
  • Will mature tree roots eventually interfere with a building’s foundation or septic system? Will it’s branches scrape against walls, roofs or hang over the neighbour’s yard?
  • Will the tree drop fruit, seeds, twigs or large amounts of leaf debris on your sidewalk or deck?
  • How close are you to a road or parking area? Pavement impedes water and air from getting to the tree’s roots. Air pollution and road salt are very hard on many kinds of trees.

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Growing Conditions:

Next, lets look at what trees need. Different trees need different growing conditions.

Soil

  • Determine your soil’s texture. Sandy soil will not retain water or contain many nutrients. Clay soil has lots of nutrients but may not drain well. Silt soil may not drain at all. Most soils are a combination of sand, clay and silt and will benefit from the addition of organic matter. Seee Soil Types and Soil Texture for more information.
  • Test your soil’s pH, if very acid or very alkaline, it will affect a trees ability to access soil nutrients. There are home test kits available or you may send a soil sample to a soil testing laboratory in Ontario. See Soil Testing Laboratories List for more information.
  • Evaluate your subsoil especially if you live in a new subdivision. Newer subdivisions often have a thin layer of topsoil on compacted subsoil. You may need to replace some of the subsoil with topsoil or at least break the subsoil up so that the tree will not develop a shallow root system. A tree’s roots need to be able to spread out to access water and air.

See All About Soil for lots more information on soil.

Water

  • Water is necessary for the tree roots to absorb nutrients and for other life processes. Some trees prefer more water while others prefer a well drained site and there are lots of variations in between. How much moisture will be available to your tree?

Sun

  • Buildings, other structures and other trees can shade the soil. Many trees need full sun but many will tolerate partial shade. How much sunlight will your tree receive in a day?

Plant Hardiness Zone

  • The plant hardiness zone of your potential tree planting location will indicate the weather conditions that your tree needs. In Canada, the zones are based on maximum temperature, minimum temperature, rainfall, snowfall, frost free period and wind. See Plant Hardiness of Canada to figure out your plant hardiness zone.

“Which Tree do I Buy” Example:

You love trees that flower. You have decided to plant a tulip tree in the small courtyard of your condo in Peterborough, great, they grow in zones 3-4 … so far so good for the Peterborough area. However, tulip trees can grow over 35 m (115 ft) according to the University of Guelph, so a tulip tree is not a good choice for the tiny yard of a condo. The mature tree will be far too large!

In summary, make a list of what you want and your specific growing conditions. We have many locally owned plant nurseries nearby. The staff will use their expert knowledge to help you choose a tree appropriate for your needs and growing conditions.

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Additional Resources

Arboretum at the University of Guelph

Ontario Trees and Shrubs

Plant Resources, Landscape Ontario – scroll through has lots of info on various kinds of trees