I have some busy lizzies in pots that have got powdery mildew. I have destroyed the plants, but what I would like to know is can I put the compost in the compost bin or will I have to get rid of it?
Certified GKH Gardening Expert
It is best to get rid of all plant materials and soil which have been in contact with powdery mildew and to not compost them. A very hot compost pile could kill powdery mildew fungi, but most compost piles won't get hot enough, so there would still be the risk that the compost would spread powdery mildew to your plants next year.