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.
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.
- 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!
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