Powdery Mildew on Rosemary Plants

Symptoms

• Powdery mildew is a fungal disease affecting many garden plants. True to its name, it shows itself as a gray or white powdery film on leaves and tender plant tissues. On rosemary, powdery mildew tends to be white, covering both the needle-like leaves and stems.

Site Selection

• Choose a site in full sun that allows your rosemary to grow to its full size. Air circulation is key to preventing powdery mildew on garden plants. Cut back overhanging branches from nearby plants.

Harvest

• Harvest rosemary branches throughout the season. This thins out the plant, increasing air circulation. Use rosemary in recipes, flower arrangements and potpourri.

Indoors

• Rosemary planted indoors should be given a warm, sunny spot with good air circulation. Snip the plant regularly to thin and water only when the soil becomes dry.