Why Do My Sweet Alyssums Look Unhealthy?

Are the seedlings dying?

Are the stems and roots rotting?

Are the flowers covered with gray mold?

Are the leaves yellow and wilting, stems blackened at the base and the plant is toppling over?

Do the leaves have dark, yellow-bordered spots on them?

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.

Fungal wilt causes stems and roots to rot. white fungal strands may be visible around the plant base. Plants growing in well-drained soil are less susceptible. Discard damaged plants. To avoid transferring the fungus to healthy plants, wash your hands and gardening tools after handling infected plants.

The likely cause for these symptoms is the fungal disease - Botrytis blight. Other symptoms include brown to black spots that may appear on leaves and petals. You can only prevent Botrytis blight disease by planting sweet alyssums in areas with good air circulation. Water sweet alyssums sparsely. Infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

Stem rot causes these symptoms. These problems are common when sweet alyssums are kept in a place where too much shade prevents the leaves and soil from drying out. Remove and destroy infected plants and surrounding soil. Let the soil dry somewhat between waterings and incorporate organic matter to improve soil drainage. Avoid overwatering and overcrowding. Keep winter mulch away from the crowns to prevent excess moisture.

Dark, yellow boarded spots on leaves indicate the fungal disease - Leaf blight. Spray foliage with fish emulsion or with sulfur to prevent the spread of mild infections.

Some environmental issues or growing conditions may have caused your plants sickly look. Alyssum likes full sun and well-drained average soil. Water regularly for best growth, even though alyssum can tolerate temporary drought. Use a general-purpose fertilizer once in spring. Excess fertilizing gives ample foliage but few flowers.