When the winter cold begins to bite, there are several things you can count on – heavy jackets, snow shovels, and a cloud of depression that encircles New England until about late March or early April. While most of us hunker down inside, killing time before the arrival of more agreeable temperatures, our plants are subjected to all kinds of winter related stress that we may not even notice until later next season.
Here are the most common stresses you can expect your trees and shrubs to experience during this winter:
Desiccation of FoliageEvergreens hit hard by the strong rays of the winter sun are stimulated into transpiration, causing a loss of moisture through the leaves that is not replaced while the ground remains frozen. The result is a browning of foliage due to damage of the leaf tissue, which takes on a dry, brittle appearance. This can be exhibited by only a portion, or the entire leaf surface. Treatment with an anti-desiccant spray can help prevent this damage by creating a protective, waxy layer over the surface of the leaf that will hold in moisture
Winter Storm DamageWinter is storm season here in Massachusetts, which means heavy winds, snow and ice. A good old-fashioned weather event is all it takes to display the structural defects in our beloved trees and shrubs. Weak branch unions, pockets of decay, excessively heavy limbs, and/or previous root damage all create opportunities for failure when Mother Nature flexes her muscles. Assessing the needs of your plants and taking appropriate action ahead of time (pruning, cabling, bracing, etc.) is the best way to prevent serious problems all year round.
Death from Temperature Fluctuations and DroughtWhen established plants die, it is often due to compounding factors. The widespread drought experienced throughout the area is expected to increase plant fatality over the course of this winter. Fluctuations in temperatures at the beginning and end of the season present the greatest opportunities for plant damage as they receive mixed environmental signals that create a greater vulnerability to tissue and cell damage. This was manifested in many species of flowering cherries over the summer, where major sections and even entire plants collapsed with the onset of warmer temperatures. Sometimes, severe cold like we experienced last February can actually freeze and kill the cells inside your plants, similar to frost-bite in humans. These plants never emerge from dormancy, or they appear normal but display irregular leaf expansion and poor flower production during the next growing season. Selecting appropriate plant material for each specific hardiness zone is key to the long term success of any landscape.
Salt Damage to Your PlantsSodium Chloride is widely used as a de-icer during winter. It is mixed with sand and applied to roads, driveways and walkways throughout the state by municipalities, contractors and homeowners. The effects on deciduous plants are sometimes hard to diagnose, but on evergreens the damage begins in late winter as a browning of the needle tips. The damaged area may then expand to encompass the entire plant. Obviously, damage will be more severe on the sides of the plant facing any roads or walkways where these salts were applied. On heavily traveled roads, salt spray by passing cars and trucks can extend the damage a great distance horizontally and vertically. Plant foliage can be somewhat protected with burlap. However, this does nothing to negate salt buildup in the soil, which simultaneously blocks useful nutrient uptake and decreases available water for plants. Gypsum should be applied at the beginning and end of the winter season to help mitigate the effects of salt accumulation in the soil. Avoid using these salts around sensitive species. As alternatives, use sand, calcium chloride, and calcium magnesium acetate.