Preparing Trees for Winter
Do not prune your tree until all leaves have fallen off of the tree.
- The "no prune" time frame is variable, but usually begins late-August to early-September.
- The tree is preparing for winter by translocating sugars (stored energy) made by the leaves to branches, the trunk, and to the roots.
- Active tree root growth occurs in late summer and into fall. As long as the soil is warm enough, above 45° F, the roots will continue to grow.
Water and Aerate the root zone around the tree.
- Use a deep root water attachment on your garden hose. (Deep root watering information.)
- Soil should be damp for deciduous trees and moist (wetter than damp) for evergreen trees. Although evergreens are not actively growing in the colder months, water is still lost through the leaves. In Wyoming, with dry and windy winter months, providing water to evergreens is critical. Depending on precipitation frequency and amount, evergreens should be watered adequately at least twice a month, more often if it has been warm, dry, and/or windy.
- Avoid watering trees, especially evergreens, prior to windy days.
- Remove grass from around tree bases as lawn grass competes with tree roots for water.
- Be careful not to overwater. Soil needs to be porous, containing small spaces between soil particles. These spaces are filled with air and water. If the spaces are completely filled with water or compacted, then air is excluded. Roots provide water and nutrients for the tree. They need air (oxygen), water, and nutrients for themselves to grow.
Provide a ground mulch underneath the tree.
- Mulch can be any porous ground cover: wood chips, bark pieces, porous landscape cloth, and rocks. Do not use fine materials such as grass clippings or saw dust. The fine materials can hamper water and air movement into the soil. They can also cause the loss of nitrogen in the soil to due to a high decomposition rate.
- Keep all mulches at least 3 to 6 inches away from the base of the tree trunk.
- Limit the depth of mulches to 3 to 4 inches.
- Mulch acts as a temperature buffer, and helps in soil water retention.
Provide shade to the trunk of young deciduous trees. Except aspen trees.