Pruning, according to the Purdue University Extension, is not required to shape young orange trees, but the pruning of mature trees is required to increase fruit production and to prevent disease. The best time of year to prune, says Arizona Cooperative Extension (ACE), is between February and March for desert growing varieties, and late February to March for cooler areas. Pruning is done prior to blossom.
Remove sprouts as they appear recommends the Texas A & M Extension. Sprouts appear at the base of the tree and steal valuable resources such as water and nutrients from the main tree. Remove sprouts at the base using pruning shears, or by breaking them off by hand. ACE recommends keeping the lower 10 to 12 inches of the trunk free of sprouts.
Remove branches that are dead or damaged. These branches may cause disease if left on the tree, according to ACE. Remove them using hand pruners or loppers.
Remove branches that are crossing each or rubbing against each other to increase fruit production. Cut smaller branches using hand pruners or loppers. Remove branches larger than 1 1/2 inches in diameter using the three-cut method.