What Is Making My Cilantro Sick?

Are there very small water-soaked spots between leaf veins that enlarge and turn dark brown to black?

Are there any small water-soaked lesions near the base of petioles that become soft, sunken, and brown?

Are the leaves yellow and red, plant growth is stunted?

Are the seedlings dying and the stems are girdled or rotted at soil line?

Are the leaves covered with white powder?

Are the leaves curled and yellow?

Are there singular, or closely grouped circular to irregularly shaped holes in the foliage?

Are the seedlings clipped off at the soil line?

Bacterial leaf spot diseases are known to attack cilantro. Other symptoms include stems that may have elongated dark streaks and inflorescences that are yellowing, and turning brown and blighted. Bacterial leaf spot is difficult to control. Plant only pathogen-free seeds, from a reputable nursery. Avoid overhead irrigation. Do not work with plants when they are wet.

These symptoms indicate bacterial disease Soft rot. Bacteria thrive in oxygen-depleted plant tissue. Disease emergence requires long periods of water-saturated soil. Plant coriander in well-draining soils. Allow plants to dry before watering. Avoid wounding plants during harvest to prevent the development of the disease.

Carrot motley dwarf is a disease caused by carrot redleaf virus together with carrot mottle virus. Both viruses must be present to cause carrot motley dwarf. Avoid planting coriander near overwintered carrot fields. Control aphids as they are likely to vector the virus.

If your seedlings are falling over and the stems are girdled or rotted at the soil line, the most likely cause is a damping-off disease. Remove and destroy all infected plants. To prevent damping-off let the soil surface dry between waterings, thin seedlings to avoid overcrowding and do not add nitrogen fertilizers until plants have developed leaves.

White, powdery patches on the leaves are caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining them and any surrounding plants. Water plants from bellow to keep foliage dry. Any affected leaves should be cut off and removed. Any commercial fungicidal spray will protect your plant from further infections.

Distorted, curled leaves are caused by aphids. These tiny insects can vary in color, green, pink, black, gray to completely white. They cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted, and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Armyworms are known pests of cilantro. The insect can go through 3–5 generations a year. Organic methods of controlling armyworms include biological control by natural enemies that parasitize the larvae and the application of BTK spray (Bacillus thuringiensis).

If the seedlings of your plants are cut off at the soil level, most likely cause are cutworms. These caterpillars can be 1-2 inches long, brown, or gray. They feed at night by cutting off young plants and sometimes eating them whole. During the day, they are hidden below the soil surface. Control them by introducing parasitic nematodes to the ground. Using BTK spray on the ground will also control their numbers.

Yellow, stunted plants and roots that have swollen galls indicate root-knot nematodes. Other symptoms are plants wilting during bright, hot days. Prevent root-knot nematodes by applying chitin or introducing parasitic nematodes to the soil before planting. Solarizing the soil also helps in preventing root-knot nematodes.