Now, where were we?
I’m so glad to be back! Winter kill, was it? I don’t know if there’s been a worse year for it. Everywhere I look, desiccated evergreens are everywhere.
I’ve got native species, you know, the one’s you’ve banked on overwintering for you, going completely brown, while well-covered “sensitive” varieties did quite well under a blanket of snow (my Japanese Maple made it, I’m happy to say!).
I needn’t point out this was a terribly loathsome winter and it may be a forecast of what’s to be expected in our ever-changing global climate.
We have to be more vigilant in protecting our investments, particularly if they are mature and don’t have the benefit of snow-covering.
Winter desiccation, or “winter kill” as it’s colloquially known, occurs when the amount of moisture lost from a plant’s foliage is more than it has obtained via its roots.
It’s particular mostly to evergreens like pine, spruce, cypress, and even boxwood and rhododendron. You might notice that one side is more damaged. This could be because of the prevailing winds or if the tree or shrub is located against a home where radiant heat is causing it to dry out.
Your tree or shrub might be susceptible if it has been improperly planted, if it hasn’t received a good fall watering or if insects have weakened its immunity.
Here’s the thing. Your tree isn’t dead. That’s wonderful news, particularly since a mature tree would be a shame to lose.
I can think of a home in my neighbourhood with two lovely weeping cypresses adorning the front doorway that have gone completely brown. To the gardeners I say, hold fast!
Once the brown falls away, new growth will emerge, provide they water plentifully and offer some kind of fertilizers.
Wait until new growth has emerged before pruning back branches. Cut back to about a quarter-inch above the live bud. Cutting back is an important step, as the dead stuff can be an open door for fungi or insects to take hold.
So, how can you prevent winter kill next year?
A product that’s available that I’ve had success with is an anti-transpirant, like Wilt-Pruf. I picked mine up at Southview Greenhouse when I was worried about my Japanese Yew not overwintering.
At such a price, I couldn’t bear to think of it not surviving. You spray the product on leaves of particularly susceptible species, like Japanese Yews and Alberta Spruce, and it acts as a flexible coating that doesn’t interfere with a plant’s regular photosynthesis or respiration.
Apply after the shrub or tree has gone dormant (November, typically). For other, less sensitive plants, a mulch base of 3-4 inches in a three-foot ring should prevent water run off.
I water as late and as much as I can, until the ground freezes, really. Usually, I empty my rain barrels this way. I’m not wasting my good water and I clean out my barrels in a single shot.
You can relocate trees, if necessary, and never underestimate the power of a good burlap shawl. Even native species can benefit from a good covering up.
Anne Boulton is an avid gardener who lives in Sudbury. Visit her blog at greenboots.ca.