10 Tips For Winter Care Of Woody Ornamentals

LINDA GEIST

COLUMBIA, MISSOURI

 The arrival of a new year brings the coldest weather of the season.

Extremely low temperatures, frozen soil, rapid temperature changes, drying winds or lack of soil moisture all may work to make plant survival a challenge, said University of Missouri Extension horticulturist David Trinklein.

“Even with our best efforts, some damage is possible,” Trinklein said. “However, gardeners can reduce the chances of damage developing by following 10 simple tips.”

1. When adding plants to the landscape, Trinklein advises using only plants that are well adapted to the area. The USDA Plant Hardiness Zone Map helps in choosing perennial plants based upon the average low temperature expected in your area.
2. Plant trees and shrubs in well-drained soil unless the plants in question have adaptability for poor drainage. One of the most damaging conditions in winter that weakens plants is poor drainage.
3. If fall has been dry, water trees and shrubs well before the soil freezes to ensure adequate soil moisture to carry the plants through winter. Even dormant plants without leaves continue to lose water during the winter through their bark and twigs.
4. Mulch around the base of trees and shrubs. This will increase moisture retention and decrease the depth of the frost line. Mulches also prevent alternate freezing and thawing of soil as air temperatures fluctuate, which can result in frost heaving of shallow-rooted species.
5. Unless they can be moved inside or otherwise protected during the winter, do not plant small trees or shrubs in containers. The roots of woody plants are more susceptible to cold temperature injury than their shoots. Since the winter soil temperature inside an aboveground container can be very close to air temperature, a plant’s root system often is lost to freeze damage.
6. Wrap the trunks of newly planted or thin-barked trees with tree wrap or other materials such as spiral plastic protectors. This reduces the chance of winter sunscald or frost cracking of the trunk by discouraging abrupt temperatures changes.
7. For newly planted or marginally hardy evergreens, construct windbreaks on the south and west sides of exposed plants to prevent sunscald and desiccation. Screens should be 2 feet away from the plants and tall enough to shade them from the winter sun.
8. Anti-desiccants also provide some protection for broad-leaved evergreens or for newly planted trees and shrubs. In some areas they can substitute for windbreaks. Temperatures must be above 40 F at the time of application, which must be repeated every six to eight weeks.
9. Tie together branches of multi-stemmed evergreens with a strong cord to prevent ice or snow from disfiguring or breaking the plants. Plants covered with snow normally are better off if you leave them alone rather than attempt to remove the snow via shaking or raking.
10. In early spring, as soon as any winter-damaged branches or twigs can be detected, prune them out. Application of a complete fertilizer in March or early April helps to stimulate new growth and repair wounds of damaged plants.

“Trees and shrubs are an important part of the landscape and often represent a significant investment,” said Trinklein. “Both the investment and appearance of the landscape can be protected by following a few simple rules before the wrath of winter is upon us.”   ∆

LINDA GEIST

UNIVERSITY OF MISSOURI