Lemon tree leaves curling is a common symptom of several disorders, and it’s important to understand the underlying causes of this issue to ensure the health of the tree. A few of the more common causes of lemon tree leaves curling are related to environmental circumstances, inadequate care and nutrition, and the presence of plant pests or diseases.
Environmental Conditions
Environmental conditions like temperature, wind, and light can cause lemon tree leaves to curl. In temperatures above 85°F and below 75°F, the leaves are likely to curl, and even at 75°F and higher, the leaves may curl if they’re exposed to direct sun. Below 45°F, the leaves may curl due to frost. Additionally, high winds can cause the leaves to curl if they don’t receive the proper amount of shade and shelter.
Inadequate Nutrition
Adequate nutrition is crucial for healthy lemon tree leaves, and any nutrient deficiencies can cause the leaves to curl. Nitrogen is especially important for lemon trees, so be sure to provide an ample supply of this nutrient. Additionally, applying fertilizer regularly (usually between March and August) is important to keep the leaves from curling.
Care and Maintenance
Inadequate care and maintenance can lead to curling leaves, especially if the tree doesn’t receive enough water. Lemon trees should be watered twice a week, the soil kept moist and the tree’s foliage should never be allowed to dry out. To ensure optimal growth and health, be sure to weed and mulch the tree regularly.
Plant Diseases and Pests
Plant diseases and pests can cause lemon tree leaves to curl, and it’s important to inspect the tree regularly for any signs of disease or pests. Pests like aphids, whitefly, and mealybugs can all cause the leaves to curl, and diseases like a citrus canker or verticillium wilt can also lead to curling leaves. If the tree is afflicted with pests or disease, be sure to take the necessary steps to treat and remove them.
Fungi
Fungal infections such as powdery mildew and black spot can cause lemon tree leaves to curl. These fungi thrive in hot, dry conditions, and they usually affect the older leaves on the tree. To prevent fungal infections, water the lemon tree early in the morning, maintain adequate spacing between plants, and keep the foliage dry.
Growth Restrictions
When a lemon tree is restricted in growth due to its location or the shape of its pot, its leaves can curl due to lack of light, oxygen, and water. To correct this, make sure the tree has enough room to spread its branches, and check that its roots are not restricted in its pot.
Herbicide Damage
Accidental exposure to herbicides can cause lemon tree leaves to curl, and this can be especially harmful if the herbicide is applied in high doses. Make sure to be aware of any application of herbicides in the area and to use one that is labeled safe for use around citrus trees.
