Spruce Spring Damage

In my last column I had made a prediction that the early warmth of this spring followed by many nights of sub zero temperatures would cause damage to trees. Well, unfortunately, it turns out that I was right.

The vast majority of trees in the region have fared surprisingly well. I was expecting some early leafers like cherries and willows to suffer extensive leaf damage from cold exposure. That didn’t materialize but what has become more than obvious is that white spruce trees across the region are experiencing widespread needle loss.

I’ve been receiving calls from residents in our region as far away as the Geraldton area about this problem. If you look at the majority of spruce trees in just about any location, you will notice the needles are showing a greyish colour and falling off the twigs. The needles on some spruce are turning red before they fall off.

Fortunately many trees within the urban limits of Thunder Bay and along the lake have been spared from this damage because of the temperature buffering effect of Lake Superior.

Conifers are often the hardest hit trees when winter temperatures rise. If daytime temperatures rise consistently while the ground is still frozen and covered in snow, the trees cannot pull moisture from the roots to replenish that lost in the needles. In seasons like this, the advantage a conifer has over leaf trees of using needles for several consecutive years becomes a detriment to their health.

For the most part, the affected trees will rebound and survive just fine. They won’t re-grow needles where the old ones were lost but the existing buds should flush out and develop normally. Some trees that are already stressed may not be able to survive with only the new shoots and may not survive the next few years.

If you own some affected spruce trees and would like to help them, you could water their roots and add mulch from the trunk of the tree out to the dripline and beyond. Remember that when you are watering, the absorptive roots are out towards the dripline and not by the trunk. Adding water to the root flare of the tree can lead to decay problems that can destabilize the tree.

If you think your tree may not make it, don’t lose hope and fire up the chainsaw yet. They may open more slowly but you should see bud swelling and shoot elongation of new growth over the next two weeks.