What are the most common problems when growing rosemary?

Rosemary is generally resistant, but has some potential issues including aphids, spider mites, whiteflies, powdery mildew, and root rot. These problems arise due to overwatering, inadequate drainage, high humidity and insufficient air movement. Diseases are not a problem when grown in well-drained soil in full sun and if watering is avoided. Check plants frequently for damages due to pests; prune away infested leaves when needed; and naturally control pests with neem oil or insecticidal soap.
know more about how to grow rosemary