Question about dormancy
I have a fantastic tuberous begonia that was purchased from a local nursery in late winter in full bloom. I kept it in our sunroom, and it has been in flower since. In the last few weeks, the flowers have started to get papery and whitish, and have been falling off. A few leaves also have a green and yellow spoty appearance, resembling black spot on roses. I thought mildew, but our sunroom is cooled and while it is >90F outside, it is around 70F in the sunroom with lower humidity. I am thinking that although there is a fungal infection, it is also time for the plant to get ready for dormancy...and my continued watering has aggravated the mildew/fungal infection since the flowers subsided before the leaves looked so bad.
I plan to keep it shady and dry and let it go into dormancy so I can pot it up mid-winter.