What is wrong with my Celtuce plant?

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

Are the flowers covered with gray mold, leaves may be blotched or discolored?

Are the seedlings dying?

Are there dead plants scattered around the field, plants are stunted with small leaves and stems?

Are there any small, angular, gray-brown spots with defined darker red-brown margins on leaves?

Are the plants rapidly wilting and dying, often without turning yellow, small black fungal bodies may be present on the surface of the root just below the soil line?

Are the leaves yellowing, wilting and, dying?

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 large or small holes in leaves, damage may be extensive?

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.

Gray mold on flowers is probably caused by fungal disease - Botrytis blight. You can prevent Botrytis blight disease by planting in areas with good air circulation. Water plants sparsely. Severely infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

If the seedlings are dying the probable cause is a damping-off disease. Damping-off is caused by various soil fungi. Damaged seedlings can't be healed so, the best course of action is to remove them. 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.

Bacterial wilt causes these symptoms. It can be diagnosed by plants that are wilting during the day and recover at night. This disease occurs wherever alfalfa is grown, and it is one of the most important diseases in the US. Resistant cultivars are the only method of management.

These symptoms indicate fungal disease - Septoria leaf spot. This disease is most severe during rainy seasons in closely planted gardens. It usually appears when the plants begin to set fruit. Remove and destroy infected plant debris. Don't handle or brush against plants when they are wet. Rotate plantings. Remove weeds growing nearby.

Sclerotinia stem rot (white mold) is a fungal disease that causes these symptoms. Wet weather conditions favor this disease. The disease is usually introduced to non-infected areas by infected seed. Plant only certified seed. If the disease is known to present rotate crops with non-hosts such as cereals.

Yellow leaves that wilt and die usually indicate Root rot disease. Poorly drained, overly wet soil promotes rot so choose well-drained sites and add organic matter to improve drainage. Remove and destroy infected plants. Solarize the soil before replanting.

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, most likely cause are 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.

Cabbage looper is a caterpillar that sometimes attack celtuce. Looper populations are usually held in check by natural enemies, but if they do become problematic larvae can be hand-picked from the plants. The application of BTK will effectively kill younger larvae.

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.