Pinch back tips of new growth to help round out citrus trees. Cut back erratic new growth or trunk suckers not wanted above the graft union. Head back upright growth to limit the size of a citrus tree.
Mature citrus trees can be pruned to remove dead, diseased, or broken branches. Prune also to admit light to the fruit–but only if the branching and leaf cover is excessive.
Citrus trees store their food in their leaves; the amount of foliage on a tree is directly related to the amount of fruit the tree will produce.
The best citrus pruning practice is to remove unwanted growth while it is still small. Pruning early in a tree’s life will make pruning of mature trees almost unnecessary.
Citrus trees can be trained to a high branching structure–with the lowest branches several feet above the ground. But citrus branches can be allowed to “skirt” the tree–that is hanging almost to the ground. The fruit on skirted trees is easier to reach–and weed growth is controlled. Full skirted trees are less susceptible to bark and fruit sunburn which is important in hot and dry regions.
Orange and grapefruit trees require very little pruning; their twiggy growth will fill out into a full, rounded shape. Lemon and lime trees have an upright growing habit; vigorous lemon growth may require pinching or heading pack to keep a pleasing shape.
Thinning and heading back will result in the loss of some crop. Shaping is best done early in the tree’s life–when the tree is smaller and pruning is easier; this will allow for heavier fruit yield in later years.
Pruning Older Trees
Older, neglected citrus tree can be pruned to restore shape. Remove dead, damaged, or diseased wood first. If extensive pruning is required, prune the tree so that the main scaffold branches remain. Newly exposed bark–the trunk and interior branching–should be protected from sunburn by the application of indoor latex white paint or protective paper or cloth wraps. Citrus bark is thin and easily damaged by sun exposure; sunburned bark will become hard and brittle and may peel.
Cold Weather Damage
Foliage and branching damaged by frost or freezing weather should not be thinned or pruned away until new growth begins and the damaged area is clearly defined. Minor frost damage includes yellow, droopy, and wilted leaves. Leaves that have been frozen will shrivel and drop from the tree; they may remain on the tree for several weeks without drying or turning color before dropping. Allow new growth to begin before pruning away frost or freeze damage; do not prune until the threat of frost is past. Remove damaged fruit immediately after a freeze.
Citrus trees damaged by frost or freezing weather may require major pruning or removal. Do not begin this process until the extent of the dieback is clear; this could be several weeks or months after the freeze.
Citrus that has been heavily pruned should be only lightly fertilized. Keep the ground just moist, but do not overwater freeze damaged or heavily pruned citrus.
Many citrus trees have thorns. Use heavy gloves, goggles, and pruners suited for the size of the tree and branches you are pruning.
Gardening Tips: The Kitchen Garden Grower’s Guide