My 7-year-old black mulberry has canker and is looking very sorry for itself. Only half the tree has leaves, what few berries there were dropped off early, and it is definitely sicker than it was last year when it started looking unhappy. It's in a damp climate (East Cornwall) and sits in the middle of a lawn. The tree has grown slowly (the garden was laid on top of a former school playground, so I had to dig the hole in the Victorian equivalent of hard core) but until two years ago looked healthy and produced fruit.
I have two questions: 1. Is it better to cut off the affected branches immediately (but run the risk of excessive bleeding from the stumps) or wait until winter when the tree is dormant (but give the disease more time to spread)?
2. Do I treat it with anything after the pruning? Extra feed? Mulch? 3. If it is too far gone (whenever that is) so needs to come out, would it be safe to get another black mulberry? And should I avoid using the same spot?
Any tips would be great.