How to Identify Sooty Mold on Plants

If you find black, moldy patches on your roses or other plants, you might be dealing with sooty mold. Sooty mold is a problem usually caused by an infestation of insects carrying the disease, and it's usually very easy to identify if you know what symptoms to look for.

Difficulty:

Moderately Easy

Instructions

1. Look on the upper leaf surfaces. If you see the tell tale black color which comprises the cells of the sooty mold colonies, then you most likely have sooty mold on the plants.

2. Check the newly sprouted leaves. If the young leaves are sticky, you might have a sooty mold problem. This, along with other symptoms, is a more definitive identification of the disease you're dealing with.

3. Know which plants sooty mold affects most often. The plants most affected by sooty mold are birches, camellias, citrus trees, lindens, oak trees, plum trees, roses, catalpa, hibiscus, juglans and willow trees. Keep a special eye out for sooty mold on these susceptible species of plants.

4. Examine your plants for infestation of insects. Sooty mold typically develops on plants infested with insects, such as aphids. The mold grows on the by-products these insects produce and leave on your plants.

5. Watch for two kinds of sooty mold growth. The black coloring on the leaves consists of deciduous growth, which only lasts until the leaf dies. The other type-persistent growth begins on the stems, branches and trunks of woody plants or trees and renew from the previous season's sooty mold colonies.