I have a problem with primarily my clematis. The leaves have started to
go brown round the edges. I left if for a while hoping it was nothing,
but it has spread all over the plant and the leaves seem to be
crumbling. It has spread to my montana which grews next to the said
clematis. I do not believe it to be clematis wilt as it now seems to be
affecting a shrub which is in close proximity. I think it is some kind
of fungus similar to mildew. Any advise?