Grapefruit trees (Citrus X paradisi) are believed to be an accidental hybrid between the orange and the pommelo. The grapefruit tree can grow quite large, up to 45 feet tall, and bears thorny branches. The fruit of the tree, while juicy, typically has an acidic flavor. Optimal growing conditions for grapefruit include warm weather and 36 to 44 inches of rain annually, dispersed evenly throughout the year. Like other citrus, grapefruit trees do not require heavy pruning and some areas of the tree should be left alone. Do not top your grapefruit tree--cut off the top to control its size--until it is 5 years old. Prune in the spring.
Sharpen your pruning equipment or have them sharpened professionally. Dull pruning equipment can leave jagged edges, which may harbor bacteria and fungi.
Remove trunk sprouts. These will appear, in the first several years, as new growth sprouting from the trunk near the bottom part of the grapefruit tree. If they are small enough, rub or break them off by hand. Larger sprouts require pruning shears to remove.
Remove dead and broken branches and twigs in the fall. Also remove any twigs crossing over others.
Prune the top of the tree to bring it to the desired height. This should only be done after the tree reaches 5 years of age.
Remove any weeping branches on the lower part of the tree only if diseased or damaged, as these protect the bark from sunburn.