How to Get Rid of Curled Leaves on Meyer Lemon Trees

Leaf Miner Strike

• Burrowing insects called citrus leaf miners cause curling leaves on Meyer lemon trees. Larvae of the citrus leaf miner moth tunnel through young leaves, damaging and distorting leaf tissue. Other symptoms include squiggly lines on leaves. Only Meyer lemon trees under 4 years old suffer significant damage from citrus leaf miners. To avoid attack, don't prune trees more than once a year and don't apply nitrogen fertilizer during summer and fall, when leaf miner populations are largest. Spray upper and lower leaf surfaces on heavily infested young trees every two weeks with an insecticide containing 0.5 percent spinosad, diluted at a rate of 2 fluid ounces per gallon of water, or according to the manufacturer's instructions.

Psyllid Skirmish

• Sap-sucking insects called psyllids lay eggs on emerging Meyer lemon tree leaves, and the feeding nymphs inject a toxin that causes leaves to curl and distort as they open. Psyllids are most active when temperatures are between 68 and 86 degrees Fahrenheit, and a single female can lay 300 to 750 eggs. Spray with a ready-to-use insecticide containing 0.006 percent acetamiprid in winter, covering upper and lower leaf surfaces, to kill adult psyllids before new leaves emerge in spring. Acetamiprid is a broad-spectrum insecticide; so, spray in the early morning or at dusk, to avoid killing bees and other beneficial insects.

Aphid Attack

• Clusters of green, yellow or red insects within curled Meyer lemon tree leaves in spring are a sign of an aphid infestation. Often farmed by ants for the sweet, sticky honeydew they produce, aphids suck sap from leaves and distort young growth. Aphid infestations rarely cause significant damage, and a blast of water from a garden hose removes excessive colonies. To deter ants from farming aphids on lemon trees, prune foliage that is in contact with other structures and wrap tree trunks with a collar of heavy paper about 1 foot from the ground; then, smear it with ready-to-use sticky insect-trapping material. Check the material every two weeks, and reapply if it becomes clogged with debris.

Water Violation

• Meyer lemon trees require constantly moist soil, but overwatering causes curled leaves. If the ground beneath lemon trees is soggy and their leaves are curling upward, stop watering immediately and allow the ground to dry out to a depth of 1 inch before watering again. Water trees within the drip line, applying 10 gallons of water for each inch of tree trunk's diameter at knee height. An average garden hose supplies 10 gallons of water in 5 minutes. Water consistently afterward so that the ground stays just moist.