I'm new here but love looking through all the fantastic threads on here. I'm looking for some advice about overwintering Geraniums. I've heard people say that it's not worth overwintering them and that they should be treated as an annual, but I really loved the colour of my Geraniums last year and so wanted to see if I could keep them in the greenhouse and get another year out of them.
I didn't water them for a week or so prior to placing them in the greenhouse, then cut them back and pulled off all the foliage. Then just left them in the greenhouse to go dormant. They had been in there a good 2 months or so andI hadn't touched them at all (hadn't watered them as I assumed if they were dormant they wouldn't need it), but when I checked on them last week, there was a fine white powdery dust all over them. I was wondering if it was powdery mildew. I read online to spray them with a fine mist of diluted milk to prevent the spread of the mildew. So I did this. But when I checked on them this afternoon, all the stems are turning brown and seemingly rotting. I'm so disappointed.
Does anyone have a way to resolve this? Is there anyway I can revive these plants or are they goners? What's the best way to store them over-winter? Would it be best to up-root them, shake off any excess soil and let them dry out (out of compost) in the garage?
Any advice would be much appreciated,