There are two general kinds of Bamboo: The runners can pop up many feet from the original plant, and eventually form a fairly large open grove if not curbed. Runners are wonderful in long narrow spaces, along walls or fences for example, though they are healthier if the narrow space is at least 3 feet wide. There is a product called rhizome barrier that can curb them, and it's best to install it before planting.
Clumping bamboo has a completely different habit -- it forms a larger and larger roundish clump, and it is not as suitable for planting in long narrow spaces. Clumping bamboo is not really invasive at all. It stays in a clump, and does not travel all over one's yard, but the clump can tend to grow quite large, and some clumping bamboo is giant!
|Clumping "Alphonse Carr"|