By Richard Jauron
Extension Horticulturist
Winter has officially arrived in Iowa, and with it comes snow. How will it affect landscapes? Are there steps that can be taken to alleviate winter’s effects?
Here are some tips from Iowa State University Extension and Outreach horticulturists on how to help plants and shrubs adjust to winter. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or hortline@iastate.edu.
Is snow beneficial to landscape plants?
A layer of snow is beneficial to many plants in the garden and landscape. A layer of snow protects plants from extreme cold and the drying effects from sun and wind. A layer of snow also prevents repeated freezing and thawing of the soil which can heave perennials, such as garden mums (Chrysanthemum spp.), Shasta daisies (Leucanthemum spp.), painted daisies (Tanacetum spp.), and coral bells (Heuchera spp.), out of the ground, causing serious damage or death. Additionally, a layer of snow moderates soil temperatures. Without snow, the soil may get extremely cold, damaging roots of trees, shrubs and perennials.
On the negative side, the weight of heavy, wet snow can break the branches on trees and shrubs and destroy the shape of multi-stemmed arborvitae and junipers. A deep layer of snow also deprives rabbits and deer of food on the ground, forcing them to browse on trees and shrubs that stick above the snow. Heavily browsed trees and shrubs can be destroyed.
My shrubs are flopping over due to the weight of heavy, wet snow. What should I do?
The weight of heavy, wet snow can cause considerable damage to small trees and shrubs. When heavy, wet snow accumulates on small trees and shrubs, gently shake the snow from their branches or carefully brush off the snow with a broom.
To prevent the weight of heavy, wet snow from damaging arborvitae and other multi-stemmed evergreens, wrap the plants with twine or rope in fall.
Several small spruce trees are buried in snow. Do I need to uncover them?
There is no need to uncover the spruce trees. The snow will not suffocate the evergreens. The snow acts like an insulating blanket and protects the evergreens from desiccating winter winds.
However, rabbits may browse on the spruce trees as the snow melts and portions of the trees stick out of the snow. Check the evergreens on a frequent basis through the winter months. If browsing damage is noted, take immediate steps (fencing, rabbit repellents, etc.) to prevent additional damage.
Source: iastate.edu