Hello, This is very embarrassing but i can't lie. i bought some bamboo last spring and it was doing great, very green and growing nicely on my balcony. I stopped watering it in late September, yes thats right i have not been watering it at all. About a month ago i started watering it once every week but today i had a closer look and it's in really really bad shape. Can anyone tell me if it will come back over the next few months? If so can someone please suggest how i go about pruning it, or should i even do this? I tried to get all the dead leaves of without cutting anything and the pictures attached show what is left. Also i noticed some almost moldy leaves and some white miniature fluff all over it, i am guessing these are aphids, yikes. Any advice of what i should do would be appreciated.
Cut the dead culms out at/near ground level, leave the ones with green leaves to the left of the photo, and hold off the watering. Bamboo needs little water in the winter, regular watering when it's shooting and during hot weather. A good indicator is the leaves: a bamboo in dire need of water will curl its leaves. If this is not happening during the winter, no need for water. The white fluff is probably webbing from bamboo mites. Since you're not dealing with a large plant, I'd pluck off the worst affected of the remaining leaves, scrape/wipe the white webbing/mites off the remaining leaves (they are tenacious) clean up the dead leaves and culms, and burn them (if you can't burn 'em, bag them and put them out for recycling). The dead culms aren't mite damage: either cold damage, overwatering, or a combination of both. If it's cold damage, the rhizome will send up new shoots this spring. If it's overwatering, it might still shoot if you hold off on the water for now: alternately, if the rhizome is rotting, the remaining culms will eventually die off as well, and you'll have to start with a new plant.
You can also use an insecticide suck as Malathion or similar to try to deal with the problem. If your pot has drainage holes, than you've most likely nearly starved it to death. Easiest thing to do, of course, is to pull it from the pot and actually have alook at what you're dealing with. Also, when soil has been that dry for that long, it tends to actually repel water, so if you've just started watering it again, and you see it draining from the pot quickly, fill the tub and soak the bugger! Quite literally - leave it for at least an hour. Even through the winters here in Texas (monsoon season), I frequently find that my soil has become hydrophobic after only a week, and in the worst cases, I actually have to physically penetrate the surface of the soil with a sharpened wire to allow the water an entry point. Blending your soil better also helps with this problem, but that's neither here nor there...