Why Does My Alstromeria Look Unhealthy?

Are the roots dark brown, plants wilt, yellow, and die?

Do your plants have wilted leaves and dried stems that don’t respond to watering?

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

Are there any mottled or streaked leaves?

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

These symptoms indicate a fungal disease - Pythium Root Rot. Remove and dispose of any affected plants. Do not overwater plants. Pot in the pasteurized soil mix. Apply a copper-based fungicide to protect plants.

These symptoms could indicate a fungal disease - Rhizoctonia Root Rot. Improve soil drainage by working some compost into the top ten inches. Discard all infected plants. Do not overwater plants. Pot in the pasteurized soil mix. Apply a copper-based fungicide to protect plants.

Gray mold on flowers is probably caused by fungal disease - Botrytis blight. You can only prevent Botrytis blight disease by planting flowers 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.

Mottled or streaked leaves are caused by tomato spotted wilt virus or Hippeastrum mosaic virus. There is no cure for infected plants. Remove and destroy all alstromeria plants that have the symptoms. Viruses are spread by aphids and thrips so the best way of preventing the disease is to control these insects.

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.

If the leaves are distorted and curled the culprits are 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.