We're in the grip of deep and numbing cold in Northwestern Ontario. Each day as I wince at the thermometer reading, I wonder 'how cold is too cold' when it comes to our plants, shrubs and trees?
There's good news and bad news.
Around the northwest region, most perennials are safely covered with plenty of snow. Snow is the great insulator. It keeps the ground from freezing too deeply and damaging roots. Plants that are hardy for Zones 2-3 should survive.
That's the good news.
Shrubs and trees, on the other hand, are more at risk of winter damage. I am thinking of landscape specimens we plant in our gardens and around our house foundations rather than the hardy native species that grow in the forests of our region.
There's good news and bad news.
Around the northwest region, most perennials are safely covered with plenty of snow. Snow is the great insulator. It keeps the ground from freezing too deeply and damaging roots. Plants that are hardy for Zones 2-3 should survive.
That's the good news.
Shrubs and trees, on the other hand, are more at risk of winter damage. I am thinking of landscape specimens we plant in our gardens and around our house foundations rather than the hardy native species that grow in the forests of our region.
Tree showing breakage from heavy snow.
Recent reports of ice damage to trees in southern Ontario have been heartbreaking. The heavy weight of ice and snow can flatten shrubs and bend or break the limbs of deciduous trees. Ice makes branches brittle which means removing ice can break branches. It's best to leave them alone. Snow on the other hand can be removed from shrubs and smaller trees with a broom by pushing the broom in an upward motion.
Evergreens are also susceptible to damage. "Sunny days in winter, or wind, can cause evergreen leaves to lose water or 'transpire'," says Dr. Leonard Perry, at the University of Vermont. "Since the ground is frozen, roots can’t take up replacement water, so the result is the leaves drying out and browning." The winter-scorched needles will eventually drop off.
Euonymous showing signs of winter scorch Broadleaf evergreens such as euonymous (Euonymus fortunei) and rhododendron can also be affected by scorch.
According to Dave Clement, a plant specialist at the University of Maryland, "Leaves curl and droop, then brown from the tips and margins, giving the leaves a scorched appearance. In many cases damage occurs during the winter months but symptoms appear in the spring as the plant begins to emerge from the winter dormant period and move into the spring growth phase."
This is all bad news, indeed.
What can we do to protect shrubs and trees from winter damage? Like so much in the garden, being proactive is key.
According to Dave Clement, a plant specialist at the University of Maryland, "Leaves curl and droop, then brown from the tips and margins, giving the leaves a scorched appearance. In many cases damage occurs during the winter months but symptoms appear in the spring as the plant begins to emerge from the winter dormant period and move into the spring growth phase."
This is all bad news, indeed.
What can we do to protect shrubs and trees from winter damage? Like so much in the garden, being proactive is key.
Tips for Winter Protection
- Plant varieties that are hardy for your zone.
- Plant shrubs and perennials where they are protected from cold wind.
A fence, evergreen hedge or structures can provide a windbreak.
- Add a layer of mulch.
After the first freeze, additional mulch will reduce water loss from the soil and reduce the heaving that occurs as the soil freezes and thaws in late autumn. - Stop feeding plants quickly-available nitrogen in late summer.
Let them harden off – slow their growth – before cold weather sets in. - Water deeply.
Ensure shrubs and trees – all plants – receive plenty of water in the soil so that their tissues are well hydrated going into the winter. - Make use of snow.
As snow arrives, if it is not too heavy, gently shovel it in and around shrubs. This is especially helpful for broadleaf evergreens. Even the euonymous on the north side of our house survive when tucked in with the white stuff!
Photo credits:
Thermometer - therebloomsagarden.com
Snow damaged tree - University of Maryland Extension
Euonymous - Viette Nurseries
Want to read a little more?
Understanding winter hardiness
Growing azaleas and rhododendrons in the north
Thermometer - therebloomsagarden.com
Snow damaged tree - University of Maryland Extension
Euonymous - Viette Nurseries
Want to read a little more?
Understanding winter hardiness
Growing azaleas and rhododendrons in the north
