December 28, 2013
1 - Snow accumulate around the base of trees and shrubs can provide insulation and moisture.
Yard and Garden December 28, 2013
Snow has been sitting around my new fruit trees and some shrubs for several weeks. I was wondering if that could hurt my trees. Should I shovel the snow away from my trees?
Snow is an excellent insulator and protects the roots and base of the trees from cold weather. When I lived in Montana, I sometimes helped the State Climatologist by reading soil frost tubes. It was interesting to see how the soil froze to a greater depth during open winters when there was little or no snow cover over the soil. The snow was a very effective insulator. Snow will also provide moisture to the soil and help protect the trees from drying during the latter part of winter that is often dry in New Mexico.
Irrigating frozen soil is difficult because water will not penetrate the frozen layer of soil. Of course, what is frozen in the frozen soil is water, so frozen soil is not dry. However, the lower layers of the soil may be dry while the surface is moist and frozen. The snow cover around the tree will help maintain moisture in the soil and as long as the soil is not frozen, snow melt will provide moisture. The snow insulation will help prolong the time in which water can infiltrate into the soil by delaying or preventing freezing of the soil around the base of the tree.
One concern is the fact that a pool of water around the base of a tree can freeze and damage the base of the trees. This is because water expands as it freezes, when it expands it can crush the base of tree trunk. A small cone of soil around the base of the tree can help prevent crushing damage. In New Mexico, this is a minor concern, but still worth considering.
A greater danger for the base of the tree is wounding caused by shoveling the snow away from the tree. As you remove the snow, you may risk damaging the base of the tree. Leaving the snow as around the base of the tree is probably the best course of action.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!