What Is Wrong With My Bok Choy Herb?

Are there any small, round reddish brown spots with white to grey centers on the upper surface of the leaves?

Do the leaves have pale areas on upper surfaces and "downy" patches underneath?

Are the roots enlarged and clublike, plants are stunted with yellowish leaves that wilt during the day?

Are there mottled dark and light green patterns on leaves?

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

Are the roots riddled with slimy, winding tunnels?

Are there any tiny holes in leaves?

Do the leaves have wandering, white or translucent tunnels in them?

Are the leaves curled and yellow?

Are the seedlings clipped off at the soil line?

Are there any 1/4 of an inch long, yellow-white, and spindle-shaped maggots in the soil?

Do the leaves have large, ragged holes in them?

These symptoms indicate Alternaria leaf spot. Warm, wet conditions favor this fungal disease. Spray infected plants with copper and/or sulfur to prevent further disease development. Plant only pathogen-free seed from a reputable nursery.

Pale areas on upper surfaces of the leaves and "downy" patches underneath are caused by Downy mildew. This fungus spreads quickly during cool, wet nights and warm, humid days. Leaves will wilt and die. Remove and destroy all affected plant parts and encourage good air circulation around plants by thining them. Water plants early in the morning to make sure they dry before nightfall.

Enlarged and clublike roots are most likely caused by fungal disease - Clubroot. Remove and destroy any infected plants. Applying lime to the soil can reduce fungus sporulation.

These symptoms are caused by the Turnip mosaic virus. Destroy diseased plants. Presoak seed in a 10 percent bleach solution before planting, or choose resistant cultivars to prevent problems. Control aphids, because they spread viral diseases as they feed.

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.

If the roots are riddled with slimy, winding tunnels, the cabbage is infested by cabbage maggots. These small larvae feed on the roots and transfer bacterial and fungal diseases. Remove and destroy infected plants. Solarizing the soil will help reduce maggot populations in problem areas.

Tiny holes in leaves are caused by Flea beetles. These tiny, black, brown, or bronze beetles hop when disturbed. Larvae are small and white, feed mostly on the undersides of leaves. Prevent problems by covering young plants with row cover. Control severe infestations by spraying or dusting plants with pyrethrin.

These symptoms indicate leafminers. These tiny white, maggotlike larvae feed inside leaves. Prune off and destroy all infested leaves. Cover plants with row cover until flowers open to prevent adults from laying eggs on plants. Certain nematodes can attack leafminer larvae inside leaf tunnels.

Distorted, curled leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

If the seedlings of your plants are cut off at the soil level, the most likely cause is cutworms. They feed at night by cutting off young plants and sometimes eating them whole. Control them by introducing parasitic nematodes to the ground. Using BTK spray on the ground will also control their numbers.

These larvae are called Seedcorn maggots. Adults are small flies. Apply parasitic nematodes to the soil before planting to control soil-dwelling pests. Prevent adults from laying eggs on or near seedbed by covering it with a large piece of row cover after planting.

Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.

If the flowers are deformed the culprits are Tarnished plant bugs. Trap them with white sticky traps or treat plants with a commercial pyrethrin spray or dust in the evening to control severe infestations. The best way to prevent this pest is through a thorough fall and spring cleanup. This will prevent it from overwintering.