Prevent and Assess Winter Damage to Trees And Shrubs
Photo By: Julie Martens Forney
Photo By: Image courtesy of Todd Brooks
Photo By: Image Courtesy of iStock
Photo By: Julie A. Martens
Hardy Trees Can Withstand Winter's Harsh Conditions
Snow and ice can be beautiful in the winter garden. It's peaceful to observe the serenity with a cup of hot chocolate from the comfort of your living room. It's fun to share photos of winter beauty on social media with friends. It's not fun, however, to discover winter damge in your landscape. Take precautions before the cold weather hits to prevent winter damage to your valuable landscape plants. If spring arrives to show that something was overlooked, cold damage can often be mended with a little elbow grease.
Ice storms can do worse damage to some trees and shrubs than others. The threat to hardy plants is stem breakage. This can be repaired by pruning the broken branches to create clean, easy-to-heal cuts. Some marginally cold hardy plants, particularly if they are evergreens, may also exhibit foliage burn or stem dieback. Again, damaged branches may be pruned away. Burnt foliage will often hold on the plant until new leaves emerge in spring.
Heavy snow loads may break branches, or even bend flexible branches and flexible trunks out of shape. Knock snow off as soon as is practical to minimize the amount of time the branches stay in an unnatural position as well as the possible long term effects.
Sometimes gardeners enjoy the challenge of growing plants outside their cold hardiness zones. For several years there may be no incidents due to mild winters. When a "real" or more severe winter hits, those marginal plants are the most susceptible. Even in a microclimate that may be warmer than the surrounding area, these fair weather shrubs may suffer from leaf burn, leaf drop, stem dieback or even complete dieback. Many shrubs will rebound after damaged tissue is pruned away, even to the point of cutting the plant to the ground. Shrubs have a wonderful ability to store energy in their roots and send suckers up that will become the new plant.
Immediately Noticeable Damage
In the aftermath of an ice storm, damage is readily noticeable. Address obvious damage as soon as possible after it appears.
Delayed Appearance of Damage
Winter damage can be delayed in appearance, such as in deciduous trees and shrubs. Effects of road salt runoff or salt spray drift can take time to accumulate, masking the true cause of the damage over time. Regardless of when it appears, it is always the right time to prune away dead woody tissue. Whenever you discover dieback on trees and shrubs, try to determine the cause so that you may take steps to prevent further issues.
Brown Foliage Doesn't Necessarily Indicate A Dead Plant
Burnt foliage may appear suddenly, or may take time to develop, depending on the species and the exact cause. Don't assume that a brown-leaved shrub is dead. Nick the bark in a few places to see if it is still green: still green means still alive. It can take months to regenerate new growth after brownout, or it may not survive after all. Unfortunately the only way to know is to wait and see.
Ice Buildup Can Cause Unexpected Damage
Ice may build up in hollows of trees, such as where dead branches have fallen away. If these hollows stay full of water and ice, the freeze/thaw cycle can cause cracks and splits to form, which weaken trees making them susceptable to wind damage. If you are aware of a hollow that may catch rainwater or melt water, drill a hole in the tree to allow it to drain.
Keep Trees And Shrubs Hydrated
If they are stressed by drought, trees and shrubs have a much greater likelihood of sustaining cold damage. Water them well in a dry summer or fall. Pay special attention to newly planted trees.
Protect marginally hardy trees and shrubs during exceptionally cold, icy, windy or snowy weather by covering them. A breatheable material is superior to plastic because it will not allow condensation to form, which can burn foliage.
Frost blankets may not provide much insulation, but they do protect from excessive drying wind. Young plants, or those growing in containers may get the greatest benefit from a frost blanket.
Winter Bloomers Present A Special Concern
Winter bloomers, such as camellias, may be 100% cold hardy for your zone, be well hydrated, mulched and covered with a frost blanket but still lose their buds. The problem arises from the combination of the depth of cold and the state of the buds. If your hardy winter bloomers are showing color, even with the buds still closed, a deep cold snap may call for supplemental heat to salvage the flowers. A string of incandescent Christmas lights may just do the trick.
Cold Weather? No Problem
With an eye to the weather forecast and preventative action, limiting the landscape's exposure to most kinds of winter damage is no problem. Those few incidents that are unavoidable are fixable. Stay warm!