Best Way to Prevent Different Kinds of Diseases When Growing Herbs

Damping Off

Stems of seedlings rot at soil level. To prevent, water seedling trays from the bottom and maintain good air circulation and soil drainage. Cover seeds sown indoors or directly in the garden with a thin layer of finely milled sphagnum moss (available at garden centres).

Downy Mildew

White fluffy growth on underside of leaves; yellow spots on upper side. Remove infected leaves; this is most effective if the disease is caught early. To prevent, avoid overhead watering and ensure good air circulation and soil drainage.

Leafspot disease

Round or irregular blotches of fungus on leaves. Avoid wetting leaves; water soil at base of plants, not foliage. After working near diseased plants, wash hands and disinfect tools by wiping with rubbing alcohol.

Powdery mildew

White powderlike mould on upper side of leaves, particularly common on bee balm. If caught early, remove infected leaves or branches; cut back bee balm to the ground to stimulate fresh growth. To prevent, keep plants well watered, and thin clumps to improve air circulation.

Root, stem, or crown rot

Fungus causes stems to discolour, wilt, and die. Remove diseased plants promptly. To prevent, improve soil drainage and keep mulch a few inches away from plant crowns.

Rusts

Small orange or brown spots on leaves. The best control is to remove diseased plants promptly.

Wilts

There are many types of wilt diseases, each specific to a single plant or a group of plants in the same family. Wilts may be bacterial or fungal in origin. Sudden, severe wilting of the plants (when the soil is dry) is the primary symptom of all; sometimes plants also develop streaks or turn yellow. There are no effective organic or chemical controls for wilts Remove diseased plants promptly. After working near diseased plants, wash hands and disinfect tools by wiping with rubbing alcohol. Avoid growing that type of plant in the same spot for at least three years.