I planted a black bamboo tree in my backyard last year. It has just started to sprout several times all within inches of the original plant. I am concerned that the sprouts will spread and ruin our pipes underground. Does anyone have information on how deep the roots go into the ground and how much spreading occurs with the black bamboo? Is black bamboo clumping or spreading? I read it was clumping and that is why I purchased. Thank you very much Kristine
Black bamboo (Phyllostachys nigra) is a spreading type. Its roots go somewhat deeper, in my experience, than those of other phyllostachys species. It does not, however, spread quite as quickly as some (like P. decora, which would be down the block by now). You can contain it by digging a trench and installing some kind of impermeable barrier, such as asphalt roofing tiles, down to a depth of 3 feet. You can also contain it by growing it in the middle of a lawn and just mowing around it, which will decapitate the spreading canes. When a spreading bamboo is contained, you can keep it from getting too congested by cutting out, annually, some of the oldest canes (about one-third of the total stems seems to work pretty well). I'm not sure this bamboo would really pose a thread to your pipes. It would tend to snake its way around solid objects, I should think.