Lemon trees are the most cold-sensitive of all the citrus fruits. Because of this, southern portions of Texas including South Central Texas are the only parts of the state where lemon trees may grow in the ground. In other parts of Texas, lemon trees must be grown in containers. Pruning lemon trees is not a labor intensive process. Maintenance pruning is limited to controlling the tree's size and removing diseased branches and damage to the tree by sudden cold.
Wait several months after a sudden freezing spell to remove damage. Often, damaged limbs will produce leaves, but the leaves will wilt. Once this wilt occurs, you will know which branches to remove.
Remove branches smaller than 1.5 inches by cutting through the tree limb where it meets the trunk, just outside of the ridge caused by the adjoining bark. Make your cut at a 45 degree angle sloping downward and away from the tree.
Cut away branches larger than 1.5 inches with a saw. You will make three cuts to remove the limb to prevent bark stripping. The first cut should start at the bottom of the limb and move upward one-third of the way through the limb. This cut should be made 15 inches along the limb from the trunk. The second cut should be 18 inches from the trunk and should start at the top of the limb and extend downward to remove the limb. The last cut should remove the stub left behind. Position your saw just outside of the bark ridge next to the trunk and cut downward at a 45 degree angle sloping away from the trunk.
Remove any tiny trees that appear around the base of the lemon. These are sucker trees that grow from the tree's roots. If your tree is a grafted variety, the sucker tree will be different than the grafted tree.
Time rejuvenation pruning so it's done a short time before a major growth flush. Remove the tallest branches from the tree, but do not remove more than one-third of the tree's total height at a time. The lemon tree will regain its natural shape during the next growth flush, and will produce more abundant fruit.