My first response disappeared so will try again. I know little about Botrytis Blight so do your plants' symptoms match or could it be something else? Are the blooms affected? Several growers are experiencing problems with rot this year because of the amount of rain & cooler conditions, perfect for the spread of fungal diseases. I would check Dr. Optimara for any treatment. Some of these type diseases spread so quickly that the plant is gone before you can treat.

For the time being, I would separate your healthy ones, increase your air circulation, & try to control moisture and humidity. You can also cut out any rotted areas & at least apply cinnamon or sulfur if you have it.

I'm curious as to why you think you have mites. Do your plants have tight centers? Are the center leaves twisted or grey, brittle, extra hairy, or cup under? Mites are nasty critters so you want to make certain you have them & not a cultural problem. Pictures would be helpful.

Terri