In article , Franz Heymann
writes

My first 3 decades of gardening were on the Bagshot sands.
The past 2 decades have been on good loam, very slightly on the acid side,
less than 6 inches on broken sandstone bedrock. I have never been aware of
deleterious fungal problems.

I'm on soggy clay. I have lost one to a fungal like thing - there
appears to be a grey fungal blob at the base of all the leaves on one
stem, then all the leaves on that stem go brown and die, and gradually
the whole plant gets taken over. I think one of the otehrs got it but I
caught it in time. All the rest are still flourishing.
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm