How to Get Rid of Mildew on Plants

Overview

Most plants can fall prey to mildew infections. Two of the most common varieties, powdery mildew and downy mildew, can eventually cover leaves and lead to plant damage or death. Powdery mildew is usually gray or white and leaves a powder-like substance on the leaves. Downy mildew is also white or gray but has a fuzzy or downy appearance. Basic maintenance controls and gets rid of most plant mildews unless the infection is severe or particularly persistent.

Step 1

Prune or thin plants to increase airflow, as mildews thrive in overcrowded and overly moist conditions. Remove dead stems and branches and thin out plants if they are growing too closely together.

Step 2

Prune away severely infected leaves or branches. Don't compost these, as the mildew spores might survive the composting process.

Step 3

Sanitize pruning shears and tools after pruning affected plants so you don't spread the mildew to healthy plants. Rinse them in a solution of 1 part bleach to 9 parts water to sterilize.

Step 4

Water plants in the morning instead of the afternoon. Morning watering allows excess moisture to evaporate off the leaves, and mildews do not grow in dry environments.

Step 5

Move potted plants so they receive full sunlight. Mildew often infects plants that receive too little sun and the mildew does not survive in direct sunlight well.

Step 6

Treat with a fungicide formulated for the type of mildew infecting your plants. Fungicides containing potassium bicarbonate, neem oil or sulfur combat mildew problems, according to the University of New Hampshire Cooperative Extension. Follow label directions for fungicide application amounts and methods.