How to Prune Conifers 

Prune pines in  late spring by removing one-half of the candle, or new shoot. Do not damage needle tips, because the tips of cut needles tend to turn brown. You can reduce open spaces on spruces by cutting off one-half of the leader, or terminal shoot,  in the spring when the new needles are about half developed. If the tree develops two leaders, remove the less desirable in early spring. Trees with more than one leader are weaker and less attractive than trees that have a single, strong, central leader. You can replace a lost leader by tying one of the branches in the top whorl to a vertical brace. Do this in the spring when the branches are flexible and there is less danger of splitting the wood. Keep side branches from growing out of bounds by removing the terminal bud. This not only slows outward growth but also helps to make the plants more bushy.