The cherry laurel is actually one of the most robust hedge plants. It also thrives in the shade and in less than optimal locations and is not very susceptible to diseases. If you have discovered changes in the leaves that indicate a disease of the laurel cherry, you can use our tips to identify many types of damage yourself and fight them successfully.
The most common diseases associated with laurel cherries are:
- buckshot
- Powdery and downy mildew
- leaf edge necrosis
You can recognize them by the discolored, stunted leaves or unsightly coverings on the upper or lower side of the leaf.
The shotgun disease
This fungal disease is not only found in laurel cherries, but also in the leaves and fruits of plum, peach and cherry trees. The fungus Stigmina carpophila is responsible for the infection. So far, there are no cherry laurel varieties that are completely resistant to this disease.
damage picture
The freshly sprouted leaves of the laurel cherry initially show red-brown spots about five to ten millimeters in size on the upper side of the leaf. Since the plant rejects the damaged tissue, the holes in the leaves that are typical of this plant disease develop as a result. If the infestation is severe, the cherry laurel throws off the infested foliage. Shotgun shot occurs mainly in wet years and in foggy areas with high humidity.
root cause
The fungus overwinters in the diseased branches as well as in the foliage and infected fruits of affected plants. The fungus develops its mycelium on the wounds of the branches, in which the spores form. The spores are spread by wind or rain showers.
combat
Remove diseased leaves and leaves that have already fallen and dispose of all parts of the plant in the household waste so that the fungus cannot spread further in the following year. Cut back the cherry laurel before the next shoot and thin out the bushes so that the wind can blow through the leaves.
You can treat buckshot with suitable fungicides. The agents kill the fungal spores before they infect the plant. Therefore you have to spray the laurel cherry before the first sprouting and repeat the application once or twice.
prevention
Some cherry laurel species are more tolerant and resistant to the fungal disease. Only plant such varieties in humid, foggy regions. Wind-open and sunny locations are ideal, where the laurel cherry can dry off quickly after rain showers.
Powdery and downy mildew
Harmful powdery mildew
Powdery mildew forms wipeable white to dirty-brown deposits on the upper and lower sides of the leaves, the young shoots, flowers and fruits of the laurel cherry. As a result, the leaves turn brown and die. Unlike other fungal diseases, powdery mildew mycelium does not grow in plant tissue, but thrives on the leaf surface. Only the sucking processes (haustoria) anchor themselves in the leaves and withdraw nutrients from the cherry laurel. Since powdery mildew, as an obligate parasite, is dependent on the survival of the host plant, even heavily infested shrubs can survive for a long time.
root cause
Powdery mildew is a dry fungus and occurs more frequently on warm days in spring and autumn, when dew forms at night. In autumn, the fungus forms dark spherical winter fruiting bodies that overwinter in the fallen leaves of the laurel cherry.
Harmful downy mildew
The spores of downy mildew penetrate the laurel cherry and grow inside the leaf. From here, the spore carriers reach the underside of the leaf through stomata, where they appear as a typical gray-whitish coating. Brown or yellow discolored areas become visible on the upper side of the leaf. The affected shrubs are severely weakened and can die.
root cause
In contrast to powdery mildew, downy mildew loves damp weather conditions. One-sided fertilization and poor air circulation promote infestation.
Control of powdery and downy mildew
Cut off the affected leaves immediately and dispose of them in the household waste. Do not compost the diseased parts of the plant, as the mildew survives in the soil and infects other plants when the fertilizer is applied. In the case of a light infestation, spraying with milk, horsetail, garlic or tansy can help to contain the mildew. If this is not enough, you can get highly effective fungicides on the market.
prevention
An airy location, good exposure, morning watering and moderate fertilization reduce the cherry laurel's susceptibility to this fungal disease. Preventive spraying with field horsetail strengthens the laurel cherry.
leaf necrosis
damage picture
The edges of the older leaves turn brown. The leaf gradually dries up and eventually falls off. Heavy infestation can lead to almost complete leaf loss.
root cause
In addition to environmental pollutants, the occurrence of this disease in the cherry laurel is directly related to the water quality. If the sodium content is too high, this leaf damage is common.
combat
Only use rainwater for watering.
prevention
Unfortunately not possible because the groundwater and air quality cannot be influenced.
tips and tricks
If you discover small dark green or red-brown dots on the underside of the leaf on the side of the leaf axils, it is often not a disease at all. From these nectar glands (nectarines) escapes highly sugary cell juice, which attracts insects.
SKb