Botrytis on peonies

Asked September 25, 2020, 10:54 AM EDT

Hi, sorry if this is a duplicate question, network trouble. 2 photos attached. On the close-up, can you confirm that this is botrytis, or do I need to bring in a sample for analysis? I'm treating it as such, cutting the plants down for fall and disposing of the debris safely. On the second photo, the brown and yellow plants are all peonies, 6 in all. Are they too close together? Do I need to dig some up to make space or can I just cut back some stems in the spring? Thank thou.

Sussex County Delaware

2 Responses

Thanks for your question! When did this disease first appear? It's hard to say if that's Botrytis sporulation just from the image--but it does look like there is white/gray fuzzy growth on the leaf surface. If so, it's Botrytis.

Botrytis blight in peonies usually shows up early in the season and also impacts buds/flowering. This could also potentially be peony leaf blotch, another fungal disease which has a slightly different life cycle (or a combination of both diseases). You're doing the right thing for both diseases by cutting down the plants. Here are more recommendations:

Destroy the plant tissue after cutting; do not compost because the fungi overwinter in plant debris. Improve air circulation between plants. It's suggested to plant peonies 2-4 feet apart. Either pruning in the spring or digging up plants should both be effective at spacing plants apart.

Hi, Jill, thanks so much for the quick response! I probably have both varieties of fungus, frankly.