The yellowing of lemon tree leaves is a common concern among citrus hobbyists. There are many potential causes and reasons why our lemon tree leaves may go yellow. It is important to identify the cause of the yellow leaves in order to address the problem successfully. In this article, we’ll explore the potential causes of yellowing leaves and how to address them.
Environmental Factors
Environmental factors can be significant contributors to yellowing leaves. If our lemon tree receives too much direct sun, the leaves may scorch, causing them to turn yellow. Additionally, too little sunlight can prevent the tree from producing enough chlorophyll, leading to yellowing as well. To address this issue, ensure the tree is receiving enough shade during the hottest part of the day, and supplemental lighting at night if necessary.
Nutrient Deficiencies
Yellowing of leaves can be caused by a lack of essential nutrients. The three primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K). If any of these nutrients are lacking in the soil, new leaves may start to yellow. The best way to address this situation is to have the soil analyzed and to apply the necessary nutrients, either in the form of fertilizer or supplemental amendments.
Water Logging
The lemon tree may be suffering from water logging. If a tree is over watered, the soil may become waterlogged, making it difficult for the roots to take in oxygen. This can cause the leaves to turn yellow and can eventually lead to death of the tree, especially in a sandy soil. To address this issue, ensure the tree is being watered correctly and ensure adequate drainage.
Diseases and Pests
A potential cause of yellowing lemon tree leaves is disease or infestation by pests. Common pests that can affect lemon trees include aphids, mites, and whiteflies. Diseases such as powdery mildew and gummosis can also affect the leaves and lead to yellowing. To address this, inspect the tree on a regular basis and address any issues immediately.
Improper Pruning
Improper pruning can also lead to yellowing of lemon tree leaves. Regular pruning is necessary in order to improve the health and vigour of the tree, but it should be done in moderation. Pruning too much can damage the vascular system of the tree, leading to yellowing of the leaves. To prevent this, perform regular pruning, but only remove healthy, excess growth.
Over Fertilization
While fertilizer is necessary for a healthy citrus tree, too much fertilizer can lead to an overabundance of nutrients in the soil. This can cause an imbalance, leading to yellowing of the leaves. To avoid this, be sure to read and follow the instructions on the fertilizer label. Also, do not apply fertilizer more often than once every few months.
Improper Soil pH
The soil pH should be maintained between 6.0 and 7.0 when growing lemon trees. If the pH is too high or too low, the tree may not be able to absorb enough nutrients, leading to yellowing of the leaves. To fix this, use a soil test kit to identify the pH of the soil and adjust as necessary.
Soil Nutrient Content
In order for the lemon tree to properly absorb the necessary nutrients, the soil must contain adequate levels of these nutrients. If the soil nutrient content is too low, the tree may not be able to absorb the essential nutrients, leading to yellowing of the leaves. To address this issue, check the soil nutrient content with a soil test kit and add any necessary nutrients.
Irrigation and Drainage System
An improperly functioning irrigation and drainage system can also lead to yellowing of the leaves. If the irrigation water is not applied correctly or the drainage system is blocked, the soil may become waterlogged, leading to the yellowing of the leaves. To prevent this, ensure the irrigation and drainage systems are properly designed and functioning correctly.
Fertilizer Types and Sources
The type and source of fertilizer used can also contribute to yellowing of the leaves. Using a fertilizer that is not suitable for citrus trees, or using fertilizers with a high salt content can lead to yellowing of the leaves. To address this issue, read the ingredients and instructions carefully and select a fertilizer specifically designed for citrus trees.
Mineral Deficiencies
Certain essential minerals may also be lacking in the soil, leading to yellowing of the leaves. The most common mineral deficiencies are iron, magnesium, copper, and zinc. To address this issue, check the soil for mineral deficiencies with a soil test kit and add soil amendments as necessary.
Incorrect Potting Soil
Incorrectly formulated potting soil can also contribute to yellowing of the leaves. If the soil has too much clay or peat, or if it is too alkaline, the tree may not be able to absorb enough nutrients, leading to yellowing. To address this, use potting soil specifically designed for citrus trees, and check the soil pH regularly.
