Butterfly bush fungal
John Asked
My butterfly bush came back from the harsh winter with a lot of new growth and is planted in full sun. I just noticed that a number of leaves are covered with a whitish material. I presume it’s fungal. What is the best course of action?
Thanks,
John
The Gardener’s Answer
Hi, John: Your presumption sounds correct. Butterfly bush are susceptible to a few different fungal issues. From your description, it sounds like powdery mildew is the culprit here. Spores are transmitted through wind and splashing water. Some environmental factors we have no control over, but if additional moisture is needed, water in the morning and always avoid overhead watering. A combination of hand trimming and a fungicide spray will help control spread. Trim back all affected branches and clean your pruners between cuts to prevent further infection. Choose a fungicide that is labeled for powdery mildew and follow recommended application rates. Plant selection and growing conditions are important. Some varieties are more disease resistant than others and good air circulation is important in preventing spread. Butterfly bush thrive in full sun and fertile, well-drained soil. There is still plenty of time for healthy new growth this growing season.
Angie Oakley
Kentucky Living-Ask the Gardener
