Question: I planted several arborvitae this fall. Do they require any protective measures during the winter?
Answer: Environmental factors including temperature extremes, freeze-thaw cycles, snow and ice, desiccation, de-icing salts and drying winds can cause damage to a broad range of evergreen and deciduous plants.
Snow and ice can damage trees and shrubs by bending and/or breaking branches. To prevent breakage, tie up the arborvitae with heavy twine starting at the base of the plant and winding spirally around upward and back down.
Any snow collecting on the shrubs should be removed with a broom as soon as possible. Always sweep upward to lift the snow. This will help the shrub from becoming misshapen from bending under the weight of heavy snow. Pushing downward will only make matters worse and cause further damage.
However, if the branches are frozen, the best course of action is to do nothing. Breaking the ice may cause the ice to cut the bark on the branches and weaken the tree's resistance to pests and diseases. Resist the temptation, and let the ice melt away on its own.
Desiccation causes significant damage mostly to evergreens. Damage occurs when the foliage loses water faster than it can take it up from its roots in the frozen ground. The drying out occurs more often during sunny days, and periods of strong winds. Damage shows up as discolored, burned evergreen needles.
To reduce desiccation it is important to water significantly in late autumn if there is insufficient rainfall. Mulching your trees with a 2- to 2 1/2-inch layer after the soil freezes will help maintain a more even soil temperature.
Lastly, damage to plants occurs from the use of salt for de-icing sidewalks and roads. Damage to the plants occurs above ground as well as below, and will be most evident in late winter and early spring when plants begin active growth. The salt accumulates in the soil and causes abnormal color, needle tip burn and browning that starts at the edges and moves toward the center.
To minimize damage, use calcium chloride instead of sodium chloride (rock salt). It may cost a little more, but it is less damaging. Try using other abrasives in place of salt, such as sand or sawdust. Keep salt-sensitive plants far away from roadsides or bedding edges to reduce their exposure to the salt.
Overall, most plants will survive the winter with minimal or no damage. Appropriate plant selection and site location are still the best preventative methods to reducing winter damage to your landscape plants.
Mona Bawgus is a certified master gardener and consumer horticulturist with Rutgers Cooperative Extension of Atlantic County. Write to her c/o Rutgers Cooperative Extension, 6260 Old Harding Highway, Mays Landing, NJ 08330. Email: