Heavy Snow Weighs on Evergreens
Heavy snow can sometimes build up on shrubs and break branches. Evergreens are especially vulnerable because their needles catch and hold snow that would fall right through the leafless branches of a deciduous shrub.
Branches that slant upward from the trunk, such as those on tall, narrow junipers and arborvitaes, are most likely to break from the weight of snow.
It is best to gently brush off the snow while it is still falling to keep it from building up. You can use a broom to very gently shake or brush the bush or tree. Don’t do this if the temperature is below 20 degrees; deep cold makes the wood brittle and branches may break.
If snow freezes on the shrubs, leave it alone and wait until it melts off. Trying to remove it at that point would likely damage the branches. Most of the time, evergreens survive heavy snowfalls without harm.
To prevent future snow damage to tall, narrow evergreens, you can tie the branches loosely together with strips of soft cloth or bungee cords. It is important that the ties be slack enough so that the tree can flex in the wind. Do this when there is no snow on the branches.
Snow is actually beneficial to evergreens, especially those that were planted last spring or fall and have not had time to establish a substantial root system. Snow insulates their roots and, when it melts, provides important moisture.
Evergreens need more water in their roots, stems and needles through the winter than other trees and shrubs. Without it, needles and small branches often dry out in the cold wind and die. This winter, dieback is often the cause of brown patches in the spring. If the dead branches are pruned out, the shrub will usually fill in the space with new growth in time.
Written by Tim Johnson, director of horticulture, Chicago Botanic Garden for the Chicago Tribune, January 27, 2011