There is much more to growing Christmas trees for commercial sale than just planting a bunch of conifers in a field. Christmas trees require yearly maintenance pruning to give them their pleasing, uniform shape. Early pruning should focus on training a tree into the pyramid shape characteristic of Christmas trees. Pine trees should be pruned in summer.
Prune away double leaders when the tree is first planted by cutting the weakest stem at the point where the two leaders join the trunk with a pair of pruning shears. Cut the weaker leader at a 45-degree angle starting at a point outside the growth ridge in the crotch of the tree.
Prune back lopsided growth so the tree's growth is balanced and uniform. Remove any branches that grow at a weak angle. All pine tree growth for Christmas trees should be lateral.
Remove branches that grow too close together, rub one another or grow inward toward the trunk of the tree. Remove any diseased or broken wood.
Put a glove on your non-shearing hand. Select a lightweight knife with a sharp blade for quick, efficient shearing. Swing the knife away from your body instead of toward it. Keep the gloved hand away from your shearing hand. You should also wear shin guards and safety goggles while shearing trees.
Shear the surface of pine Christmas trees so that the branches are uniform. Taper the tree so that the base width of the branches is two-thirds the overall height of the tree. Stand over small trees and cut downward to ensure the proper angle when trees are young. Follow your earlier pruning line as trees grow taller. Avoid shearing branches with no needles. These branches will not set buds or create new needles.