How do I treat a fungal infection on the clover in my lawn?

Question:

I have what appears to be a fungal infection in my clover lawn. I need help identifying it and advise for the proper fungicide.

Answer:

Jonathan Foster, Home Horticulture Outreach Professional

I’m sorry to hear about the clover problems.

I believe it’s likely you’re looking at powdery mildew, a common clover ailment in red clover that can affect white clover, too (which it looks like you have). We do not typically recommend treating it, unless the affected plant is high value and difficult to replace, as fungicides are relatively ineffective against the fungus once it is widespread. Your best approach will most likely be to pull/rake out the infected clover and replant it, while taking steps to mitigate the conditions that promote powdery mildew–you should get some regrowth into those areas by remaining healthy clover, too. The State of Maine does have some suggestions for chemical interventions if you feel strongly you need to use one (including less toxic options like neem oil), but I can’t guarantee it will knock out the infection and you may spend more on the treatment than on replacing the clover with fresh seed.

My apologies for not having better news for you, but I wish you happy gardening, nonetheless.