We're on London clay but don't usually have a problem, we have a very well established garden. We've lost too much CLKD; a Schizophragma, two Viburnum davidiis, a Caryopteris, a Clematis armandii, two Clematis Fujimusume, two Rosa golden showers and now two Trachelospermum. Majorly naffed off!!
Trouble is if it is a soil baddy and I suspect it is, we can't dig out the soil because we have huge shrubs in the beds. Hubby is suggesting we surround new plants with some sort of barrier but some of these viruses or bacterium are carried by water. I'll see what the experts say. A neighbour lost a tree a few years ago to Honeyfungus so it could be that.
Such a shame, the garden was utterly glorious last year, so so pretty. x