What Is Wrong With My Ammi Majus?

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

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

Are the leaves covered with white powder?

Are the leaves curled and distorted?

Are the leaves covered in coarse stippling and may appear silvery?

Do the leaves have large, ragged holes in them?

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.

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.

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.

Distorted and curled leaves are caused by aphids. These tiny insects 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.

These symptoms may indicate thrips. Thrips are tiny, yellow to black flying insects. Severely infected plant parts should be removed and destroyed. Control thrips by introducing lady beetles or lacewings, their natural predators. Insecticidal soap helps in severe infestations.

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.

Some environmental issues may have caused your Ammi Majus unhealthy look. Grow Ammi majus in well-drained soil in full sun to partial shade. Allow seeds to develop to save and sow the following year.