--Broad-leaf types of evergreen shrubs, such as the Oregon grape holly, should be pruned little, if at all. If pruning is necessary, prune lightly just after bloom (late spring). Occasional corrective pruning to remove unwanted shoots may be done almost any time, providing the cut is made just above a side branch.
--For narrow-leaf-needle trees or shrubs, such as pines, spruce and fir, prune according to growth characteristics. Prune those that produce side buds on the shoots, such as spruce, fir and Douglas fir, by cutting the tips back to the desired length in late winter or early spring when buds are dormant. Cut just above a side bud or side branch.
--For plants that produce few side buds, such as pines, pruning may be accomplished by pinching or snapping off with the fingers a portion of the young growth "candles" that form in late spring and early summer. The proper time to prune is when the candles snap off easily and cleanly. Avoid cutting these plants with a knife or shears. This invariably injures some of the needles and later gives the plant a general brown appearance.
--Plants with scale-like leaves and no definite buds, such as junipers and arbor vitae, may be pruned at anytime except during sub-zero weather. The optimum time for using hedge shears to prune an upright evergreen is just prior to the new growth in spring and again in late June or early July. Cutting marks will be covered up by the flush of growth.
Do not use hedge shears on spreading evergreens like the pfitzer juniper. To obtain a natural look on this type of plant, prune to an upward growing branch or bud. Careful pruning will allow the remaining lateral branch to hide the pruning cut.

Browse related Faqs by tag: horticulture, trees, pruning, colorado, evergreen