Winters in Wyoming can be difficult and are almost always windy. Extreme temperatures and constant winds often remove what little moisture remains in the soil from the previous growing season and any snow that may have fallen.

Dry soils can seriously damage root systems of herbaceous perennial plants as well as woody shrubs and trees. The reason is dry soils change temperature very quickly. They also heave, expand and contract with changes in temperature. The resulting soil movement can physically damage or destroy roots.

Moist soils, on the other hand, change temperature much more slowly, which is one of the basic properties of water. Consequently, soils kept moist during the winter are less susceptible to temperature changes and do not expand and contract like dry soils do. Keeping soil moist tends to save root systems from being damaged.

Evergreens are most susceptible to winter drying since they do not lose foliage during these months. In lawns, grass roots may die, leading to large areas of dead turf. Any plant stressed from

B-1186R

Revised April 2020

Karen Panter, Extension Horticulture Specialist,
Department of Plant Sciences, University of Wyoming

winter desiccation is more likely to succumb to disease and insect problems the following growing season.

Spring bulbs may not bloom properly. Lack of water for bulbs can lead to brown or deformed flowers or flowers that don’t open at all. Perennial herbaceous plants may show root loss, and crown buds may die due to inadequate winter watering.

If perennial plants, especially new ones, are not watered during the winter, symptoms of winter desiccation may appear during the next growing season. Symptoms usually include branch die‑back and leaf burn or even total plant loss.

Mulching and watering during the winter months can help. Mulch tends to insulate the ground and keep the soil at relatively constant temperatures. Watering fills open spaces and can help seal cracks in the soil and minimize root damage caused by temperature swings.

During the winter, when there is no snow cover, when temperatures are above 40°F, when the ground is not frozen, and when the wind is not blowing, homeowners are encouraged to get out their hoses. Water enough to moisten the soil at least six to eight inches down. Remember to drain and store hoses again to prevent ice damage to the hose or water taps.

B-1186R

Revised April 2020

Karen Panter, Extension Horticulture Specialist, Department of Plant Sciences, University of Wyoming

Editor: Katie Shockley, University of Wyoming Extension

Design: Tanya Engel, University of Wyoming Extension

December 2007. Karen Panter, Extension Horticulture Specialist, Department of Plant Sciences, University of Wyoming

Issued in furtherance of extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Kelly Crane, director, University of Wyoming Extension, University of Wyoming, Laramie, Wyoming 82071. • The University’s policy has been, and will continue to be, one of nondiscrimination, offering equal opportunity to all employees and applicants for employment on the basis of their demonstrated ability and competence without regard to such matters as race, sex, gender, color, religion, national origin, disability, age, veteran status, sexual orientation, genetic information, political belief, or other status protected by state and federal statutes or University Regulations.