What Tree Owners Should Know About Powdery Mildew Disease

10 June 2015
 Categories: , Blog


Are your tree's leaves covered in a white, powdery substance? Chances are good that your tree has powdery mildew disease, one of the most common fungal infections that affect plants. Read on to learn how to treat your tree, and what you can do to prevent the infection from spreading to other nearby plants.

How To Treat Powdery Mildew Disease

Before you being treating the disease, it's important to confirm that powdery mildew is, in fact, to blame for your tree's symptoms. Usually, only the leaves and twigs are affected by this condition. If your tree has cankers or sores on its trunk or larger branches, a different, more severe infection such as thousand canker disease or black canker disease may be present. These infections are often deadly, so you'll want to call a tree care professional from a company like Mead Tree & Turf Care Inc to address them.

If you're pretty sure that your tree does have powdery mildew disease, begin by trimming away any branches on which most or all of the leaves are affected. On branches where just a few leaves are affected, see if you can pluck off just those small branches and twigs which contain the powdery leaves.

Powdery mildew disease spreads most easily in hot and moist climates. If your weather is hot and moist, have your tree sprayed with a fungicide to keep the disease from returning. If you live in a dryer area, you can hold on on spraying and see whether the fungus comes back. If you notice signs of fungus after a week or two, then have the tree sprayed. Typically, fungicides that contain copper are the most effective.

How To Prevent the Spread of Powdery Mildew Disease

Most species of trees and bushes can contract powdery mildew disease, and some farm crops can get this disease, too. Thus, it's important that you burn the leaves that you trim from your infected tree to prevent the fungus from coming into contact with and infecting other plants.

You can also protect individual trees from powdery mildew disease by having them trimmed regularly. Trimming thins the branches, so the tree dries out faster after rainfall. Fungus loves water, so it will be less likely to breed on a dry tree. If you have fruit trees, having them sprayed with fungicide early in the spring and every few weeks once the fruit sets will protect your crop from powdery mildew.

Usually, powdery mildew disease is not overly dangerous to trees. However, it can weaken a tree and leave it more prone to severe infections like thousand cankers disease and anthracnose. Thus, you should never ignore a case of powdery mildew disease.