Stunted and weak rosemary

Spot diseases on your rosemary plants sooner so you can treat plants before they are destroyed by disease and can successfully manage symptoms. Examine plants daily to be sure no disease symptoms are present or emerging.

Rosemary largely resists disease, though powdery mildew can attack, especially on plants grown indoors when conditions are crowded or damp. Ensure that your plants are well-spaced with good air circulation and dispose of infected stems by tossing them into the trash. Avoid overwatering and keep the air dry.

In outdoor plants with powdery mildew, check the plants regularly and apply a fungicide when needed. Reduce the incidence of disease by pruning overgrown plants to improve air circulation within plants. (Pruning also stimulates your plants to produce new shoots.)

Another problem that may affect your rosemary is root rot, the most common problem, which stems from the plant’s dislike of having its roots in wet, soggy conditions. You can add coarse sand or grit to the soil to improve drainage.

Have you had to deal with root rot or powdery mildew in your rosemary plants? Please tell us how you deal with rosemary diseases.