Grapefruit trees (Citrus paradisi) very rarely need pruning, when grown in the home landscape. It is thought that the more leaves these subtropical, evergreen trees hold, the more fruit it will produce and the quality will be better. Prune only if the grapefruit tree has suffered damaged from the cold, needs rejuvenating, to remove dead wood or limbs that are interfering with a structure. Holding off on unnecessary pruning, will guarantee a healthier looking tree that produces a bounty of fruit.
Prune the grapefruit tree with sterilized and sharpened pruning shears or loppers. Sharp shears will guarantee a clean cut through the wood and sterilized shears will not transport disease. Dip the pruning shears in a solution of 50 percent water and bleach.
Wait until early spring to prune any live growth or frost damage from the tree. This will assure frost damaged branches are dead and the tree will not be affected by anymore cold snaps, which can do further damage.
Cut off dead branches flush to their connection to the main branch. If only a section of a main branch is dead, it is only necessary to cut off that section. The entire branch does not need to be cut off.
Cut off large limbs by first making a cut 15 inches out from the trunk, on the underside of the limb. Saw almost through to the other side. Make your second cut 18 inches out from the trunk and on the upper side. Saw at an angle until your cut meets up with your first one. The limb should crack off leaving a nub. Cut the nub by sawing from its top toward the bottom, at a downward angle away from the tree.
Prune old trees to rejuvenate them. Cut the trees branches back by one third. The tree's root system will then put energy into replacing the grapefruit tree's canopy, especially during its growth season in spring.
Remove limbs that are interfering with a structure, anytime of year. It is best to remove the offending limb before it does damage. This is the only time it is right to indiscriminately prune a grapefruit tree.
Prune any limbs that are crossing over another one. Crossing will weaken the branches on both, so it is best to remove one. Select the branch that looks the strongest and is causing the least amount of problems, to remain. Cut the offending branch, at its connection to a main branch.