You've planted some citrus trees on your property, and perhaps they've been beautiful and you've enjoyed them up until now. But there's a problem. You see lemon tree leaves curling!
After all the work you put into creating a tropical oasis in your garden, the look you desired seems to be flying out the window.
When lemon tree leaves start to curl, it can indicate one or more of a number of things.
Certain kinds of lemon and other citrus leaves can develop diseases that may cause this and other unsightly problems.
Let's go through the causes of curling lemon tree leaves and what you can do to fix the problem.
Treatment for Leaf Curling on Lemon and Other Citrus Trees
Leaf curl disease
Leaf curl disease can be addressed with a clean-up spray with a copper base. This fungicide should be applied immediately after pruning up until the first buds of spring begin to appear. The spraying should be done every 10 to 14 days.
The infected leaves that fall off the tree need to be burned or thrown away. Never try to compost them, as this will allow the disease to spread and then you'll have the same problem all over again.
What Insects Can Cause Leaf Curling
If you find that your issue with citrus leaf curl is linked to an insect problem, look for an appropriate spray to remedy the problem.
Pests that feed on sap such as psyllids, mites, or aphids attack your plant to get the juices they can extract from transport tissues.
When too many of these pests are present, they can cause leave curling and cupping. Discoloration is another common consequence.
If you think that this might be the problem, look at the undersides of your tree's leaves. You'll see some of the pests grouped together in clusters.
You can spray neem oil or insecticidal soap on your citrus tree and leaves to deal with this issue. You should do this once a week until you see signs that the problem is resolving and the pests have disappeared.
Cold Weather Can Cause Curled Leaves
Cold weather can also cause citrus leaves to curl. This is primarily because of possible frost damage. You can help to prevent this problem by covering your tree canopies with plastic or cloth sheets at night.
If your trees have only minor frost damage at this point, they will probably recover.
Inadequate Soil Water is Another Potential Cause
Your citrus trees not getting enough soil water is a possible cause of curling leaves. You may experience this problem at any time of the year, but it's most likely to happen during very hot summer days and long stretches without any rain.
In order to deal with this problem, add significant amounts of water very slowly to the trees' driplines.
The driplines are on the ground surface beneath the canopy edges). You should try to use chlorine-free water, if possible.
If your citrus trees are mature, you might have to leave a hose trickling water on the dripline for 12 hours.
You can also try applying an organic mulch. This may make it easier for the ground to keep its moisture.
Sunburn May Be Causing Your Citrus Leaves to Curl
If your citrus leaves are not only curling but also have gray, yellow, or brown spots, it's possible that sunburn is the culprit.
Sunburn is an especially significant problem for outer leaves that have the most exposure to sunlight during the warm and hot times of the year. The leaves on the west and south sides of trees will also be particularly vulnerable.
You can solve this problem by giving your trees more shade.
If it's still hot outside, it may be a good idea to leave the damaged leaves on the tree until things cool down. This is because if you take them off right away, you will expose the ones beneath.
Nutrition for Your Citrus Trees
Giving your citrus trees the nutrients they need is also essential to prevent not only leaf curling but other signs of disease, such as yellowing, fungal growth, shedding, and warts.
One common nutrient deficiency that can cause leaf curl disease is that of potassium. If your tree has a potassium deficiency, you'll likely notice leaves that are curved downwards and have a yellowish look.
A yellowish tinge to your citrus plant's leaves means that you need to change its fertilizer. Go to your local garden center or to specialized sites online to find fertilizers especially made for citrus plants.
Look for a fertilizer with a nitrogen, phosphorous, and potassium ratio of 2:1:1 respectively. Yellow leaves can also be a sign of chlorosis. This illness points to a lack of micronutrients.
Other Tips for Healthy Citrus Leaves
It's best to use a fertilizer with a higher level of nitrogen than you might find if you just chose a fertilizer randomly. Take the time needed to read and research the contents of fertilizers that you are considering.
Always ensure that the soil has the right pH. You will have to test it to determine the pH. A pH between 6 and 8 is best for citrus trees. If the pH is too low, you might end up with yellow leaves. This is because of a magnesium deficiency
A high pH of more than 6 to 8 means that the soil is too alkaline. When this is the situation, your plant will lack the right amount of zinc or iron.
If the leaves are yellowish in color and have a pointed shape at the top, they probably have a zinc deficiency. If they are pale with veins that have a darker hue, there is likely to be an iron deficiency.
If there are yellow leaves on your citrus tree,
An Ounce of Prevention is Worth a Pound of Cure!
If you haven't yet planted your citrus trees and want to prevent the problem of curling leaves and other issues in the first place, get started now. There are things that you can when planting your citrus trees that will help to make sure your plants stay beautiful and healthy over the long term.
Although it's true that some coolness will benefit citrus trees, you'll still need to shelter them indoors if you have cold winters in your region.
Citrus trees also demand deep levels of watering and they always need to be able to drain well . If you do live in a region of the world where it can get snowy and icy and you'll need to bring your trees inside, this is something for which you'll have to carefully plan.
Remember how important proper nutrition is in growing and maintaining healthy citrus trees.
As we mentioned earlier in the article, citrus trees have specific nutritional requirements that you will need to observe if you want to avoid leaf problems such as curling and yellowing.
Enjoy Your Lemon and Citrus Trees!
You now have the information you need to enjoy your garden without having to deal with the unsightly appearance of your lemon tree leaves curling.