I have an aconitum that is about 3 years old. It is about 4 feet tall and appears healthy, but has never flowered. I have other monkshood nearby that do flower, so I do not think it is a soil, light or water problem. At the tips, where the buds/flowers should be, there is a blackish withering (see photo). It has consistently done this since I have had it. What could the problem be?
I have ome that don't flower reliably, mostly the tall, late flowering ones. Napellus is OK. I've always put it down to my soil being too dry.
In the sticks near Peterborough
The blackish withering tips could be crown-rot ; check online , sometimes the only option is to discard the plant ; seems to be a soil borne disease .