In Victoria, BC winter is one of the best times of the year to prune trees.

Dormancy

Trees are dormant during the winter, meaning that they have very little sap running through their branches, this makes it easier for the tree to heal cuts made from pruning and allows the tree to retain more water.

Diseases not present

Harmful diseases and insects are not present during winter so the chance of infection is reduced. Deciduous trees (trees that loose their leaves in the winter) make their entire branch structure visible, this way branches that need to be removed can be spotted more easily.

No chance of heat stress

Trees will often become heat stressed in the summertime and pruning will make heat stress worse. The cold temperatures during winter mean there is no chance of heat stress.

No chance of sunburn

One of the worst things that can happen from pruning is sunburn. This happens after pruning when the remaining branches and foliage are exposed to more sunlight than they were prior to pruning. The extra sunlight exposure can burn the foliage and harm the tree. Fortunately, this does not happen when pruning is performed in the winter.

Winter Pruning Shrubs

Shrubs benefit from winter pruning for many of the same reasons trees do. Pruning is safer due to the absence of insects and disease, pruning is easier due to the lack of leaves and pruning has less impact due to the lack of sap flow.

Winter Pruning Hedges

One of the worst things that can happen from hedge trimming is sunburn. This happens after trimming when the trimmed hedge is exposed to intense sunlight, it quickly turns brown and in the worst cases can die. Trimming hedges in the winter months eliminates the chance of sunburn.