Citrus Tree Leaf Problems - Lemon Leaf Curl & Treatment

My lime tree which is about 7 years old, is quite green and healthy. Every year it gives me over 100 big size limes. The citrus tree does not demand a lot of attention except regular watering and fertilization 2-3 times a year.

However, there are some problems in citrus tress, specifically citrus leaf curling, yellow leaves and brown spots on the leaves. Curled leaves disease on lemon plants like limes, lemon and orange trees are a matter of concern as it may indicate significant problems.

Continue reading to learn about the causes for leaf curling in citrus trees, specially in lemon leaf curling and turning yellow and its treatment and organic control methods that really work.

Picture of  Citrus Leaf Curling due to leaf Miner.  See the white lines as the larvae tunnel through leaf tissues.
Citrus Leaf Curling due to leaf Miner.
See the white lines as the
larvae tunnel through leaf tissues.

Picture Showing   Citrus Leaf Miners Damage
Picture Showing
Citrus Leaf Miners Damage
This year there was prolonged periods of high temperatures and rain so the tree suffered a few diseases. It developed curling of leaves and their discoloration.

The picture on the left side shows my lemon tree leaf curling disease due to miner insect. Note the white lines and the white spots on the leaves, showing that the larvae has tunneled through leaf tissue.

Causes of Citrus Leaf Curl

What Causes Citrus Leaf Curl? Citrus leaf curl problem may be caused by the following reasons.

1. Pests Attack on the Citrus Tree

Aphids, spider mites, citrus leaf miners, mealybugs and scale insects are common sap-sucking pests. These pests feed on citrus leaves and suck the sap from transport tissues. This can cause deformations of leaves causing curling, cupping, wilting and discoloration.

This will not kill the tree, but they will reduce the yield.

The adult citrus leaf miner, a tiny night flying moth (see the picture) do not suck on leaf juices, but their larvae tunnel through leaf tissues as they grow, forming serpentine mines in the tender new leaves of all varieties of citrus leaving a silver trail in their path.

The mining causes the new flush to twist and curl and prevents it from expanding fully.

2. Water Stress

If the leaves are of usual green color and begin to curl inward, it may be the sign of watering problem. Apply a 3 inch layer of organic mulch around your citrus plant (do not touch the mulch to the trunk) and increase watering.

3. Fungal Diseases

Several fungal diseases like bacterial blast and botrytis disease cause the leaves of citrus tree to curl, distort, yellow, wilt and drop prematurely from the tree.

4. Bacterial Blast

If infected with bacterial blast, black lesions start on the petiole and moves to the axil and the infected leaves will curl, wither and drop.

5. Botrytis Disease

If the citrus tree has damage or injuries, then it may be attacked by botrytis disease. The infected areas due to botrytis disease develop grayish, velvet like mold causing leaf discoloration and curling and fruit drop.

6. Potassium Deficiencies in Citrus Trees

If deficient in potassium, the citrus leaves show a yellow cast that are bent downward at the tip. Check the soil pH. Feed with fertilizer high in potassium.

Symptoms of Lemon Tree Leaf Problems

The first sign of the pests problem on citrus tress is the presence of squiggly lines on the leaves and then distortion of leaves. If you see undulating white or yellow lines on the green leaf surfaces, then the problem is due to citrus leaf miners. A careful examination of the leaves can reveal tiny pests like aphids, mites, etc. on the underside of leaves.

Treatment of Citrus Leaf Curl

Picture of Adult Citrus Miner that causes leaf curl
Picture of Adult Citrus Miner
that causes leaf curl
The question is how to control curling of leaves on citrus tree? What To Do For Curling Citrus Leaves? If there is a problem of lemon leaf curling, then what should you do to control it and revive your citrus tree.

Organic Treatment of Lemon Tree Leaf Curl

The following home remedies for citrus tree leaf curling are good for all the citrus trees including lemons, lime, mandarins, oranges, etc.
  1. Cut off any damaged, curled or rolled leaves that might be hiding the pupae. Do not add these to compost bin.
  2. If you see any pests, spray your citrus tree with a solution of neem oil or horticultural oil (pest oil) or with insecticidal soap. Repeat every week until all the signs of insects are gone. I spray my lemon tree with a spray of pest and neem oil combined every third week.
  3. Do not spray the oil if it is too hot. Spray again if it rains after you spray.
  4. Some predatory insects like ladybugs, parasitic wasps and green lacewings help control pests naturally.
  5. Control of bacterial Blast: Protecting the citrus tree from high winds will help reduce the chance of bacterial blast. Apply copper sprays to trees infected with bacterial blast
  6. To avoid fungal disease on Citrus Tree
    1. The citrus tree should be prevented from mechanical injury. Applying copper fungicide before rains can prevent the fungus from reaching the fruit.
    2. Keep your citrus tree healthy, it can better withstand attacks from pests and diseases.
    3. Keep the ground under the tree clean from fallen leaves, blossoms, fruits and twigs. It will reduce the possibility of many citrus problems and even control those problems.
Organic Pest Oil for Citrus Pests | Bronze orange citrus bug