Leaf Curl on a Citrus Tree

Orange trees grow in full sun and can grow up to 25 feet tall.


Growing citrus trees provide a fresh supply of sweet, tart and delicious fruit from your own backyard. Oranges, lemons, lime, kumquats and grapefruit are only a few trees in the citrus family. Depending on the species, citrus trees grow in U.S. Department of Agriculture plant hardiness zones 9 through 12. When the leaves of the citrus tree begin to curl, you know something is wrong with the tree.


Several species of common garden pests can attack citrus trees feeding on the liquid running through the leaves. Aphids, spider mites, citrus leaf miners, scale insects and mealybugs are a few of these sap-sucking pests that will cause the leaves to curl, wilt and die. Introducing predatory insects that feed on the sap-sucking pests will help keep their numbers in check. Ladybugs, predatory wasps and green lacewings are a few of these predatory insects that help control pests naturally. You don't need to use insecticides because the pests rarely threaten the citrus tree’s life. If you decided to use insecticides to treat the pest, apply horticultural oil, insecticidal soap or neem oil to the citrus on a cool, calm day.


Several fungal diseases will cause the leaves of citrus tree to curl, distort, yellow, wilt and drop prematurely from the tree. Bacterial blast and botrytis disease are two of these fungal diseases that lead to leaf curling. Bacterial blast starts out as black lesions on the petiole and moves to the axil. The infected leaves will curl, wither and drop. Protecting the citrus tree from high winds will help reduce the chance of bacterial blast. Apply Bordeaux or copper sprays to trees infected with bacterial blast. Botrytis disease attacks citrus trees that have damage or injuries. Grayish, velvety mold begins to grow on infected areas causing leaf discoloration, curling and possible twig dieback. Botrytis disease will also cause an increase in fruit drop. Keep this fungal disease at bay by preventing mechanical injury to the tree and protecting it from rot and frost. Applying copper fungicide before rainy or foggy weather helps prevent the fungus from reaching the blossom or fruit stage.

Water Stress

A citrus tree that does not get enough water becomes water-stressed and the leaves begin to dull and curl. As the time passes, these leaves will dry, become crisp and fall from the branches. If the citrus still doesn’t receive proper water, flowers and fruit will drop prematurely, and the life of the plant is threatened. The amount of water depends on the citrus type, time of year, weather and size of canopy. For example, an orange tree with a 14-foot diameter canopy requires up to 29 gallons of water a day in July in a dry climate.


Keeping the citrus healthy and vigorous will decrease the chance of future problems. In addition, a healthy citrus tree can generally withstand attacks from pests and diseases better than an unhealthy one. Fallen plant matter -- such as fruit, blossoms, leaves and twigs -- gives an open invitation to pests and fungus. By keeping the ground under and around the citrus tree clean, you will reduce the possibility of pest and fungus problems.

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