Asiatic Lily Blight

Consider placing a fan in a greenhouse that grows Asiatic lilies to prevent fungal blight.

Asiatic lilies produce an abundance of large, trumpet shaped flowers and can tolerate cold winter conditions. Despite being hardy and requiring very little care once established, the Asiatic lily often suffers from the fungal disease botrytis blight.

Damage

The lily botrytis blight is caused from three fungus species: Botrytis elliptica, B. cinerea and B. liliorum. Infected plants exhibit tan spots on their foliage, flower petals and along the stems. As the spots enlarge, they develop a sunken appearance as the plant's cells are destroyed. The spots may grow a grayish fur covering.

Prevention

The fungus that causes botrytis blight requires moisture to grow and infect the lily plant. Consider only watering the lily plant in the morning hours so the plant's foliage has a chance to dry before nightfall. Using a drip irrigation system to apply water directly to the plant's root system will help keep the foliage dry and prevent the fungus.

Considerations

Consider removing all leaves and debris from around the base of the lily plant to prevent the fungus from growing and overwintering. When planting Asiatic lilies, space each plant so it has adequate air circulation. If the botrytis blight is severe, applying a fungicide can help prevent the disease from occurring on other plants in the garden.

References

• Maryland Cooperative Extension: Production of Hybrid Lilies as Cut Flowers
• University of Minnesota: Selecting Lilies for Your Garden
• Cornell University: Botrytis Blight
• Kansas State University Agricultural Experiment Station: Specialty Cut Flowers
• University of Illinois: Botrytis Blight or Gray Mold of Ornamental Plants

Resources

• Washington State University: Gray Mold (Botrytis blight)