I have had my bonsai (Ficus) since December and it has been going ok. But now it has started to loose all its leaves and go black where the new roots are coming through. why is this happening?
??? "..... where the new roots are coming through." What does this mean?
My Birch Tree grouping is showing some dead branches which I have cut off. Noticed some brown insects, should i spray my tree?
It's common and characteristic of Betula to have branches die back for seemingly no reason. But for trees in general, shedding of parts usually means there is a cultural problem. Your job is to determine whether or not the die back is 'birch' being true to its habits or whether it's the result of something cultural the planting doesn't like.
Re the bugs: the first step would be to identify them, and determine whether they are harmful or beneficial. Then you would determine the least noxious way to bring them under control. If you can't identify, yet are convinced they're doing damage, I've had good results with Bayer Advanced 3-in-1 insect/disease/mite control. It has a systemic insecticide (imidacloprid), a systemic fungicide (tebuconazole), and a miticide I can't remember (Tau-fluvalinate or something similar to that spelling).