The yellowing of lemon tree leaves is a common phenomenon among the citrus family. But what causes the leaves to turn yellow? While the phenomenon is highly complex, the underlying cause of yellowing of lemon leaves is relatively simple. To understand why lemon tree leaves turn yellow, one needs to understand the role of the environment, genetic factors, and the overall health of the tree.
Environment
Environmental factors can play a big role in whether a lemon tree’s leaves turn yellow or remain green. Excess sunlight or a sudden change in weather can cause sunburn, which results in yellowing of the leaves. Additionally, pollutants such as ozone from industrial emissions can cause yellowing. Furthermore, prolonged drought, cold temperatures, and even soil fertility can also affect the tree’s overall health and cause yellowing of the leaves.
Genetic Factors
The genetic makeup of a lemon tree can also have an effect on the yellowing of its leaves. Some varieties are predisposed to the condition due to their gene makeup. A citrus tree’s tendency to turn its leaves yellow can also be further exacerbated if they happen to be of similar genetic makeup. Growth issues due to age, genetics, or a combination of both may also result in yellowing of the leaves.
Overall Health
The overall health of a lemon tree can also play a role in its leaf color. Nutrient deficiencies, water deficiencies, and high salinity levels can all contribute to a tree’s yellowing of leaves. Too much fertilizer can even burn the leaves, resulting in yellowing. Furthermore, pests and diseases can weaken the lemon tree further, resulting in yellowing.
pH Level
The soil pH level can also affect the yellowing of lemon tree leaves. If the soil is too acidic or alkaline, then the nutrients won’t be absorbed properly and the leaves may turn yellow. Testing the soil and adjusting the pH level can help with having nutrient-rich soil, which will result in healthy green leaves.
Leaf Venation
Leaf venation can also be a factor in determining why a lemon tree’s leaves have yellowed. Yellow spots on lemon tree leaves are usually the result of poor vascular systems. This means that a lack of established leaf venation can lead to a decrease in chlorophyll production, thus resulting in yellow leaves.
Incorrect Watering
Incorrect watering can be another reason why a lemon tree’s leaves may yellow. Overwatering can cause the leaves to yellow, whereas not enough water will prevent the proper development of chlorophyll, thus resulting in yellow leaves. If a lemon tree is overwatered, its roots can rot, causing the leaves to turn yellow and eventually fall off.
Lack Of Nutrients
Lack of nutrients can also be a major factor when it comes to why lemon tree leaves are turning yellow. Nutrient deficiencies including nitrogen, magnesium, and iron can also result in yellowing of the leaves. Furthermore, improper fertilization or incorrect amounts of fertilizer may also result in yellowing.
Soil Infestation
Soil infestation or a pest problem can also cause yellowing of lemon tree leaves. Common infestation causes are nematodes, mites, mealybugs, and scale insects, all of which feed on plant juices and weaken the leaves, thereby causing them to yellow.
