Basil Plant Diseases

Wilting Diseases

• If your basil begins to wilt, you could have root rot or fusarium wilt. Humidity and poor circulation may promote root rot, while fusarium wilt is a fungus that spreads through contaminated soil, seeds or potting equipment.

Botrytis

• Signs of gray or white mold on harvested basil stems or fallen leaves near your basil crop could indicate the gray mold Botrytis. Since there are no approved fungicides for use on basil plants suffering Botrytis, provide your plants with adequate space for circulation and monitor frequently.

Pests

• Many insects can prey on your basil plants, including nematodes, aphids, Japanese beetles and slugs. Treating insects is easier than diseases and can be done by introducing ladybugs or spraying approved horticultural sprays.

Leaf Spots

• If your plants develop black spots in the center, they could have leaf spot, a disease brought on by overwatering and humidity.

Prevention/Solution

• Since most diseases striking basil cannot be treated by fungicide, monitor plants throughout the growing season. Do not crowd them in a bed or pot, use clean potting soil and fresh seeds and avoid growing basil in humid climates.