If you're planning to plant a citrus tree or you've already got one in your yard, you should know the proper pruning technique.
For the most part, minimal pruning is all that's required to keep a citrus tree healthy and productive. Pruning citrus trees is a different process than pruning other fruit trees for two main reasons. First, the wood in citrus trees is stronger than many other fruit trees and less likely to break under a heavy load, alleviating the need for heavy pruning. Second, while most fruit trees are pruned to allow more light through to the inner part of the canopy, citrus trees can fruit in any part of the tree that gets even a little sunlight.
Young Citrus Trees
Because pruning should be minimal doesn't mean you can get away with no pruning at all. Young trees need regular attention to grow properly. Sprout removal is the most critical task when trees are young and not well-established. Weak limbs should be carefully removed as well.
Mature Citrus Trees
Mature citrus trees still need sprouts removed regularly. They also may need judicious pruning of dead branches. Any limb that looks as if it's ailing should be removed to keep any potential problems from spreading. This also keeps a dying limb from using water and nutrients that could benefit the rest of the tree.
When you're pruning citrus trees, look for limbs that crisscross and remove them. If fruit isn't growing inside the tree, then pruning so that more light and air can get through the canopy may be necessary, but generally this is only in cases where the trees are extremely dense. If the bottom of the canopy is low, hanging down, or starting to show signs of disease, then it should be removed.
When to Prune
The best time to prune your citrus trees is February through April. Pruning, aside from sprout removal, is discouraged after May. Pruning after May can open up the canopy and expose branches to harsh sunlight. Because of the sun's intensity during the summer months, exposed branches can get sunscald or bark rot, both conditions that will eventually require branch removal.
From November to January, avoid removing even sprouts, which can cause re-growth of the sprout only to have it become damaged from cold weather, which could affect the health of the tree.
Protecting the Bark
If, after pruning, your citrus tree has wood exposed to sun, protect it with whitewash or latex paint. Bark exposed to the bright sun may become sunburned, which can cause cankers and cracking. This can lead to the decline of the tree.
Sprouts are easily removed by hand when they're small, so make removing sprouts a regular pruning task to avoid letting them grow large. If sprouts grow large, their removal is considered a larger pruning job, which shouldn't be done after May.
For branches that need to be removed, use a hand pruner or lopper. Large branches might require a curved tree saw. If you don't want a branch to grow back, prune it flush with the collar and not the trunk. This method of pruning will let the tree heal more readily and make it less likely that new sprouts will grow from the cut.
When pruning a large branch, there should be three cuts made, to ensure a clean cut that will quickly heal.
The first cut should be made 10 to 12 inches out from where your final cut will be made. Start by cutting on the underside of the branch. Cut halfway through the branch.
Next cut from the top of the branch, a few inches up from your first cut. This cut will remove the branch.
The last cut to remove the branch stub should be made flush with the collar.