Winter Plant Protection

From the desk of Bill Caras

It’s generally not possible to predict winter damage to outdoor plants. Sometimes, an early cold weather event in the Fall or a late Spring frost will harm certain plants, but what type of plants are affected varies year to year. This last Fall we had a relatively steady transition into winter and my guess is that most plants were able to achieve dormancy before any extreme cold. This is as opposed to Fall 2023 when an early cold snap in October affected a number of plant types whose injuries didn’t show up until later in the spring. Having said that, there are other factors in our control that will help plants get through the winter unscathed.

1) Sidewalk and driveway salt.

These ice melt products are used a lot more than they were even a decade ago. The danger is that they can damage or kill plants when they become too concentrated in the soil. The best way to apply the granules is to spread them out evenly and not too heavily. (When they are clumped together on the sidewalk they are quite ineffective. Once the snow/ice is gone, it is best to sweep remaining granules into piles and remove for disposal or reuse. This way they will not dissolve and wash into the surrounding soil. An added advantage to sweeping up is that remaining granules won’t be tracked into the home or office. This is a little more work but I have witnessed many trees and shrubs as well as turfgrass outright killed by salt concentrations built up in the soils adjacent to hard surfaces.

Conifers in particular can struggle when salt gets in the soil.

If you think this has happened in your yard, then we recommend applying Caras Soil Elixir which, among other benefits, contains humic acid in a microbial base which has been shown to remove salt from the soil. 

2) Pay attention to browsing.

As the winter progresses, deer become increasingly desperate for food. The result is that deer will often browse on things that they have stayed away from earlier in the year. For some deciduous plants, there is not too much effect as it is akin to a light pruning. However, evergreens can be greatly affected particularly if most or all the buds are bitten off. If this happens, spring growth will be minimal or nonexistent causing the plant to misshapen or be killed. The best deterrent is a physical barrier such as deer fencing. This fencing is far stronger than the old school “bird netting”  and can easily be cut to desired dimensions. If this is impractical, there are several sprays (which we carry) that are quite effective. 

If this is impractical, there are several sprays (which we carry) that are quite effective. 

3) Protect tree trunks.

Aside from physical damage from such things as line trimmers (weed eaters) or antler rubbing, trunks of certain varieties of trees can suffer sun scald. This usually happens on the south side of the trunk and is the result of desiccation and/or temperature differentials (between day and night).

The best way to combat this potential problem is to wrap the trunk with tree wrap. Ideally the wrap will be light in color (and thus reflect the sun’s rays) as well as being stiff enough to allow for an air gap between the bark and the inside of the wrap.

4) Some evergreens, notably Alberta spruce, are susceptible to “winter burn” where the needles turn brown over the course of the winter.

This happens most prevalently on the south facing side of the plant when the sun’s rays combine with low humidity to dry out the leaves or needles. You can provide winter shade on the south side with a material such as burlap but this can be unsightly in and of itself.

There are antidessdicant sprays - Wilt Pruf and Wilt Stop - which can be applied to the foliage. Application of these can be very helpful but this treatment should be done on warmer winter days.