Pruning and Tree Care

The leaves are eaten and tiny on my 5-year-old Plum Lucy tree and the bark is peeling. It did set heaps of fruit, but they all dropped off. What can I do to promote good health please?

My ornamental bay trees have a lot of dead leaves in the middle.  How do I bring them back to health?

What is the best time to prune roses, fruit trees and shrubs that bloom? Also when should I apply fertiliser to my apple tree?

I would love to know how to prevent gum on ripening golden queen peaches. Can you help?