dying / dead Bambusa oldhamii in los angeles
hello, i'm visiting a friend in los angeles and his Bambusa oldhamii (i believe that is what it is) appears to be dying. i can tell it was quite healthy at one time: some of the dead canes are 3 inches across. surrounded on four sides with cement, my guess is that it has completely filled the space allotted to it? there doesn't appears to be any soil left either: the ground is almost solid corms. any new shoots are very thin and don't grow very high.
what has happened, and what steps should he take to get his little bamboo forest back again? the photograph shows 1/2 of the stand. the other half is to the right.