Pruning Trees: Evergreens
With couple of exceptions, evergreens (conifers) need very little pruning. Different kinds of evergreens should be pruned based on their varied growth habits.
Spruces, firs and douglas-firs do not develop continuously, but may be pruned any time since they have lateral (side) buds which will sprout when the terminal (tip) buds are removed. It is most likely best to prune them in late winter, before the growth actually begins. Some spring pruning, however, isn’t dangerous.
Pines only put on a single tip growth every spring and then quit growing. Prune before these “candles” of new needles become mature. Pines don’t have lateral buds, so removing terminal buds will take away new growing points for that branch. Ultimately, this may leave dead stubs. Pines seldom require pruning, but if you would like to promote much more dense growth, eliminate as much as two-thirds of the length of newly expanded candles. Do not prune further back than the current year’s growth.
Arborvitae, junipers, yews, and hemlocks develop continuously all through the growing season. They are able to be pruned any time through the middle of summer. Although these plants will tolerate heavy shearing, their natural form is generally most desirable, so prune only to correct growth defects.