Can You Prune a Tree in Below Freezing Temperatures?

Pruning Time

• According to the University of Minnesota Extension, late winter or the late dormancy period is most recommended for pruning trees. Pruned trees at this time are less prone to a number of infections and cultural disorders. Many tree species are especially prone to certain diseases that are easily avoided when pruned in below-freezing temperatures.

Advantages

• There are numerous advantages to pruning trees in late winter or below freezing temperatures. This is the period just before the tree starts actively growing in the spring, so the pruning cuts remain exposed for only a short time. As new growth starts, the healing process also starts. Pruning deciduous trees, such as fruit trees, at this time is especially advantageous, as the branches are clearly exposed for pruning for good form structure.

Diseases

• Certain trees are more susceptible to diseases that late winter pruning avoids. This includes honey locust trees that are highly prone to stem cankers. If honey locusts must be pruned during the summer, do so during dry weather. Similarly, apple trees, mountain ash, hawthorn and flowering crabapples are prone to the fireblight disease. Prune these trees in late winter. Do not prune trees in fall or early winter, as this is likely to cause die back and drying of the pruned sites.

Pruning Objectives

• The main objective of pruning at the proper time is helping the tree develop a strong structure that is more resistant to wind or storm damage. Regular fruit tree pruning increases fruit yield and quality. Crown thinning allows more light into the inner canopy, reducing chances of diseases. During pruning, remove all broken and diseased tree areas. Many branches also die in time. Remove them at pruning time. (Reference 3)