Mold on Indoor Rosemary Plants

Rosemary is a hearty, fragrant herb frequently grown indoors and used for cooking. Like many indoor plants, it is susceptible to fungal diseases. Powdery mildew, often mistaken for mold, is among these maladies.

Initial Signs

• The stems and leaves of rosemary plants may initially start to look chalky as a web-like grayish-white covering spreads over them. Although the discoloration can be easily removed with a cotton swab, this will not halt the mildew growth.

Treatment

• When the discoloration is first noticed, cut away and discard the affected parts, leaving no trace of the infected parts behind in the pot or surrounding area. If the plant is heavily infected with the mildew, discard it.

Prevention

• Keep the rosemary plants in a well-ventilated area and place the pots a good distance apart. Take care not to get water on the stems and leaves of the rosemary when irrigating the plant soil. If possible, water it from beneath the pot by putting water in the plant saucer and allowing it to absorb upward into the plant roots. Treat the plant with a fungicide designed for use on indoor plants to deter mildew formation.