I've had my bonzai for almost 2 years now. It's a ficus bonsai, about 1.5m in height. I've had beautiful growth of nice leaves but after the long cold winter of 2009/2010, the leaves especially the top half of the bonsai started to fall and now there are no leaves at all on the branches. I don't see any new buds spouting out at the top half of the tree. At the bottom half of the tree, I can see now new leaves and buds spouting up.
Does anyone has a solution how to "revive" the top half of my bonsai so that new leaves/buds will sprout again?
Many thanks in advance.