Black bamboos, such as Phyllostachys nigra, are known for their ability to spread and colonise other areas of the garden, where they’re not wanted. In this Quick Tips video, Kevin Smith, BBC Gardeners’ World Magazine, gives his top tips on how to effectively restrict their root growth.
Yes, it’s easy to stop a black bamboo from spreading. Get an old, rigid pot about the size you want the clump to reach, and cut off the base. I usually do this with a pair of sharp loppers or a small saw. Plant the bamboo in the pot with the rim slightly above soil level. If you want your bamboo to form a dramatic sweep rather than a clump, let the plant spread and use a root barrier to stop it going too far. Sturdy plastic buried about 45cm deep is the best thing to use. Sink it into the earth around the plant, leaving about 5cm above the ground. Alternatively, you could bury old concrete slabs, slightly overlapping, around the plant.