Main laurel diseases – First of all it was the countryside

We use the laurel practically as an ornamental species, above all for the size it acquires in a few years and for the aroma that its leaves give off when we approach them in spring and summer.

In addition, it has a double use and that is that by harvesting its leaves, they can be dried naturally and incorporated into stews and typical dishes of Mediterranean cuisine.

However, a common problem with bay laurel is that it is visited by many pests and diseases. In this article we will only discuss diseases, one of the most common being sooty mold or fatas it is commonly called.

Other diseases caused by fungi, although not as common as this one mentioned, can also appear.

It is good to know what to do, how to prevent and cure if we detect something strange in our laurel.


read more: cultivation of cherry laurel in the garden.


List of laurel diseases

1. Smoke (fat) – smoking sp.

sooty mold on leafBidgee, CC BY 3.0, via Wikimedia Commons.

The number 1 bay disease is sooty mold or sooty mold, the scientific name of which is smoking sp. This a priori not very serious disease which affects several cultures, benefits from a preliminary attack caused by sucking insects.

Laurel sooty mold has a predilection for the sugars produced by the plant, which come out when aphids and other insects extract the juice from the sap.

In fact, it is said to be audacious of the fact that a layer of carbon is created on the leaves, generated by the mycelium of the fungus which grows on the organs of the plant.

Oily or sooty mold does not feed on the plant, only sugars excreted by sucking insects. This fungus only uses the supporting plant, although it loses its photosynthetic capacity and weakens, covering all the leaves with a black layer of “char”.

For remove fat from bay leaves You must have patience and pressure application equipment, as the best remedy is to wash and wash the leaves until the cover layer is completely removed.

Potassium soap or even dish soap (any brand will work) helps loosen the sticky sugars that form on the leaves.

It will take several applications and a lot of patience, but eventually you will get your bay leaf 100% clean.

2. Laurel powdery mildew

powdery mildew on magnoliaOidium (Microsphaera alni) present in magnolia leaf. Character font: University of Florida.

Powdery mildew is a disease present in practically all crops. It does not need high humidity conditions but it does need more or less warm temperatures, which is why it usually appears in spring and summer.

In laurel, grayish spots appear on the leaves, which is very common and also occurs with other crops.

Prevention is important, and if we detect some powdery mildew spots on scattered leaves and the meteorological conditions for its development are given (from 20 ºC and average humidity), it is better to carry out preventive treatments with sulfur.

You can use any form of sulfurin powder, liquid or suspension, abundantly wetting the entire leaf surface of the laurel (without the broth flowing to the ground).

3. Phytophthora

This neck and root fungus occurs in a wide range of crops and in almost every known plant family. It is a devastating disease because it is very resistant to treatments and can remain inactive for several years until it finds the ideal conditions to affect the bay.

In situations of high humidity in the environment and in the substrate, especially in rainy periods, the lack of oxygen in the environment activates the movement of Phytophthorawhich rises through the sap channels and obstructs the movement of watercausing visible wilting on new shoots and leaves.

It can be prevented, and in some cases cured, with the application of different forms of copper or, as a more effective treatment, using the active substance Fosetyl-Al.

4. laurel wilt (Raffaelea sp.)

laurel wiltSource: University of Florida (

This disease is particularly present in certain varieties of laurel, such as red laureland in other productive species, such as avocado.

Although it is not a very common disease in the solitary laurel grown in our garden, its effect on this crop is very obvious, as it blocks the flow of sap and causes the leaves to wilt.

This disease is transmitted by insect hosts such as ambrosia bark beetle (Xyleborus glablatus), the best way to prevent this disease is therefore to eliminate its vector with insecticide treatments.

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