Why are the leaves of my laurels turning yellow?

Posted on: June 3rd, 2015

There are a multitude of reasons why the leaves on a laurel turns yellow. The good news is, often these problems can be reversed with the right attention – and in some cases professional help.

The key to successfully treating any problem is to act quickly. Seek advice as soon as you notice the discolouration as there could be a swift remedy that will restore the plant to full health.

The list below covers four of the most common reasons for yellowing leaves on an English laurel:

• Root rot – Laurel roots can become waterlogged during periods of intense or persistent rain which creates a form of root rot or fungal disease. This will result in yellow leaves, leaf wilt or excessive drooping. One of the best ways of avoiding root rot is to avoid overwatering and standing water by ensuring excess water is able to drain away. If the root rot is already affecting your plant, consider repotting in an area in new, disease-free soil. Take care to remove infected areas of the plant prior to replanting. Sometimes an application of fungicide might help.
• Bay sucker – One of the most common pests to infest Bay laurels is the bay sucker pest. Active most in late spring, these insects feed on the sap from the plant causing extensive damage. They then lay eggs on the underside of the leaves which also suck the sap. One of the earliest signs of infestation is yellowing leaves followed by a thickening in the leaf tissue. Latter stages of disease are evident by brown leaves that eventually drop. The problem can be rectified by removing the infested foliage. The damaged cuts should be burned before treating the bay with insecticidal soap on the underside of the leaves. It is likely you will need to treat the laurel more than once.

• Nutritional deficiency – A yellowing bay laurel can be caused by a nutritional deficiency, particularly in iron. If a plant is not receiving enough iron it decreases Chlorophyll which is a vital component of photosynthesis, allowing plants to absorb energy from the sun. This results in yellow leaves at the edges. A simple solution if the soil is too damp or alkaline is to mix added nutrients into the soil to correct the pH balance.
• Drought – Yellowing leaves are classic symptoms of drought if there is no sign of disease or distress. Just as over-watering can cause damage to a bay laurel so can under-watering and it only takes a few days of no water to cause leaf discolouration. The risks are higher for newly planted laurels during the growing season which stretches from March through to October. To check soil conditions, push your hand into the soil every few days – it should always be moist but not soggy. If it feels dry, ensure you provide enough water so sink down to the root system. If you are intending to plant a new laurel, consider planting in late autumn, winter or early spring to give them the best chance to develop before hot weather arrives which will dry out the soil.

We hope you found this article on ‘Why are the leaves of my laurels turning yellow’ useful, if you would like to discuss any aspect of this article then please do not hesitate to call Prince Tree Surgery on 01277 229709