We had a beautiful 9' tall very bushy bamboo for about 8 years - with a spread of around 4' and depth of 2'. Last year, because the roots were starting to push up the paving slabs, we chopped away the creeping roots (and had new slabs!) and fitted a 4' deep root barrier around the plant, to stop the spread going under our new slabs.
At the same time, we had our compost bin hidden next to the bamboo - the plant loved it and wrapped itself around the inside of the bin so many times and to such an extent the bin wouldn't budge and we had to saw the roots out!
12 months on and the bamboo now looks very bare at the top. It's still growing new shoots (within the barrier), but the tops of the canes are virtually completely stripped of leaves and is looking very sparse. Is there anything we can do to stop this leaf loss going any further or is the plant dying? Do we need to feed it and, if so, what with?
Incidentally, the sparrows love the plant and often gather in the top of the bare stalks. We don't know if it's them that's stripped the leaves or if the leaves have simply dropped.