When was the last time you gave your lemon tree a good look over? The next time you do, check the leaves closely and look for curling or warping.
If you have found that your lemon or other citrus tree leaves are curling, it’s a sign that something’s wrong. Here’s what you need to know to fix curling leaves on your lemon, lime and orange trees, and how to prevent it from happening in the future.
What is citrus leaf curl?
Citrus leaves can curl when disease is present, temperatures are either too cold or too hot, or there’s an insect infestation, such as scale, mealybugs, mites, or aphids. Over or underwatering can also cause citrus tree leaf curl.
Whether you’re growing a lemon tree, lime tree or tending to a thriving citrus grove, curled, wilted, or wrinkled leaves are often the first visible sign that something’s wrong. If your trees are lacking water, the leaves may droop or dry out entirely, sometimes looking almost dead.
What causes citrus leaf curl?
The most common causes of citrus leaf curl are:
- Pests
- Drought
- Disease
- Temperature
- A combination of any of these issues
How to treat citrus leaf curl
The treatment for citrus leaf curl differs depending on the problem. It’s essential to diagnose whether you’ve got pests or disease, or if a weather event has affected your plant, before moving on to treating your tree.
1. Pests
Check for evidence on the underside of the leaves. Spray your citrus tree with insecticidal soap, neem oil, or a suitable insecticide from your garden centre. Repeat until the plant recovers.
Silvery lines or trails on the new leaves mean your tree has citrus leafminer. It’s a tiny moth that lays its eggs on the leaf. The hatched larvae tunnel into the leaf, creating tunnels that result in ugly, distorted leaves, thereby reducing the harvest on the trees. Spray the plant with Pest Oil or Eco Oil every two weeks, ensuring to spray both the top and bottom of the leaves.
2. Drought
Drought stress is the most common cause of leaf curl in citrus, and it is also the easiest to identify and remedy. All you need to do is give more water to your fruit trees! A great way to control and stabilise how much water your citrus trees get is to install irrigation or timed sprinklers, so they’ve got a consistent water source.
3. Disease
Several fungal diseases might also be the issues, such as bacterial blast and botrytis disease. A visual inspection of the tree and curling leaves will help you identify these diseases. Look out for pustules, unusual colours and powdery textures on the top and underside of leaves.
To treat this form of citrus leaf curl, can apply copper sprays to the infected trees. Keep in mind that spraying your tree with copper spray or a fungal spray could mean a reduction in fruiting.
4. Temperature
Drastic seasonal changes can put stress on your citrus trees. They thrive during summer, but if there’s too much heat, they can become dehydrated. Also, if it’s too cold in the winter, the leaves can become brittle and damaged from the frost.
So, depending on the climate, you can try to balance the temperature accordingly by either providing shade or removing it when you see leaves curling.
The same treatments should work for eliminating citrus leaf curl, whether you have orange trees, mandarin trees, lemon trees, lime trees, or peach trees.
Preventing citrus leaf curl with pruning
Citrus trees benefit from regular pruning to enhance airflow, promote photosynthesis, and stimulate growth.
Methods like topping and skirting can help prevent bugs from climbing onto the tree. If left unpruned, your tree will be more susceptible to the spread of diseases from contaminated soil and other infected leaves.
When is citrus leaf curl most common in Australia?
Citrus leaf curl isn’t a problem that is restricted to certain weather conditions or seasons. However, you may find leaf curling to be more common during extreme weather events, like heatwaves and frost. Observe your lemon or lime tree closely during any uncommon weather for signs of curling.
