Why are Leyland cypress turning yellow?

Answered by Tom Adger

Leyland cypress trees are known for their vibrant green foliage, so when they start turning yellow, it can be a cause for concern. There are several factors that can contribute to this yellowing, including underwatering or improper watering practices.

One possible reason for Leyland cypress trees turning yellow is underwatering. These trees require regular and sufficient moisture to thrive. If the tree is not receiving enough water, it can become stressed and start to show signs of yellowing. This is because water is essential for the tree’s overall health and functioning. Without enough water, the tree may not be able to take up essential nutrients from the soil, leading to yellowing of the needles.

Improper watering can also lead to yellowing of Leyland cypress trees. Overwatering, on the other hand, can lead to root rot and other fungal diseases that can cause the tree’s needles to turn yellow. It is important to strike a balance and provide the tree with adequate moisture without overdoing it.

In addition to watering issues, Leyland cypress trees can turn yellow due to other factors such as nutrient deficiencies. These trees require well-draining soil that is rich in organic matter. If the soil lacks essential nutrients like nitrogen, iron, or magnesium, it can result in yellowing of the needles. Conducting a soil test can help identify any nutrient deficiencies and allow for targeted fertilization.

Another factor to consider is the age and health of the Leyland cypress tree. Older trees may naturally start to show signs of yellowing as they age. This can be a normal part of the tree’s life cycle. However, if the yellowing is accompanied by other symptoms such as wilting or dieback, it may indicate a more serious issue such as a pest infestation or disease.

It’s also important to note that Leyland cypress trees have extensive root systems that can extend several feet from the initial planting site. If the tree is not planted in an area with adequate space for root growth, it can result in nutrient deficiencies and yellowing of the needles.

There are several reasons why Leyland cypress trees may turn yellow. Underwatering or improper watering practices, nutrient deficiencies, age, and health of the tree, as well as root system constraints, can all contribute to yellowing of the needles. It is important to assess these factors and take appropriate action to address the issue and ensure the tree’s continued health and vitality.