I have 3 small apple trees, 2 are new this year. The older one developed both mildew and an aphid infestation. I have treated those and can see no signs of insects or fungus yet the new leaves are still growing in curled round. The 2 newer trees are also starting to get curled up leaves though I cannot see any obvious cause. They all look rather sickly.

My japense maple has bright orange spots all over the leaves and now some branches are covered in leaves which are all orange and shrivelled up.

Help anyone please? I have tried googling diseases of both but nothing quite seems to fit.

I found this on Google, hope it helps.
Bacterial leaf spot, caused by the bacterium Pseudomonas syringae, is a severe disease of Japanese maples that causes leaf spot and branch dieback. The bacterium enters the tree through natural openings and from wounds, typically during periods of heavy rainfall or wind. According to the Oregon State University Extension website, symptoms of bacterial leaf spot include small water soaked spots, halos around the leaf drops, leaf drop and branch dieback. Because many species of Japanese maple are highly susceptible to infection, it is important to practice cultural control. Cultural controls consist of avoiding pruning and budding in wet weather, protecting the tree from frost damage, maintaining good air circulation, and avoiding fertilizer with high nitrogen counts, reports the Oregon State University Extension website. However, if infection occurs, control consists of using fixed copper antibiotics on infected trees.

My dwarf crab apple always has curly and dried leaves. I planted it under my 15" arborvitaes. I read years ago, if they area planted by them, they will get black spot and die back. It has for years. Never killing it, just not what you want.