Horse chestnut (Aesculus hippocastanum) help. Some time in the last few days my horse chestnut tree which I only planted earlier this year has developed what looks like a black mould or fungus on some of its leaves which seems to be spreading (see picture below) killing the leaves. It has been very cool and damp here recently, which i suspect my be part of the problem. Any ideas what it is and what to do about it.
I dont think so, it has stopped progressing, leaving some brown dead patches on the leaves, and most of the leaves even apparently unaffected ones are looking a little limp.
