Against brown rot? I'll try it if it becomes a problem again next year. This year is over. Does that also help against rust on roses? That is also a fungus.
yes and also against [Malvenrost]
with rapeseed oil added you deal with lice, leafhoppers and co.
Daily for a week.
May not help as well as the chemical club from the locked cabinet in hardware stores, but it helps and is cheap.
and you gardeners, does anyone watch the Chelsea Flower Show videos? I have been watching Chelsea for years and hope to be able to see it on site someday.
I watch the videos sporadically and rather by chance, visiting is certainly an experience, probably again in May next year. If visiting in May, then definitely make a detour to Hampshire in the New Forest and there to the Exbury Gardens. The other way around is probably even more recommended: Visit the New Forest and make a detour to the Chelsea Flower Show.