How to remove clumping bamboo roots?
Less aggressive clumping bamboo stands can eventually outgrow their welcome.
Unlike running bamboo (Bambuseae) that can pop up across your yard, clumping bamboo tends to stay put, even as its shoots multiply. Removal of clumping bamboo, whether to eradicate or transplant, is a fairly painless task. Clumping bamboo varieties can be found throughout the Bambuseae family in the genera Fargesia and Phyllostachys. Fargesia bamboo grows in U.S. Department of Agriculture plant hardiness zones 5 through 9; Phyllostachys species range between USDA zones 1 and 9.
Clumping bamboo roots are actually rhizomatous like running bamboo roots. But while running bamboo roots easily expand to 4 feet or more, clumping bamboo roots are much more restrained. They spread no more than about 2 inches, just enough to send up a culm -- the hollow grass stalk visible above ground -- beside a neighboring culm. This habit results in dense clumps of bamboo culms that should be dug up and divided every one to two years to prevent overcrowded roots. You can remove the root divisions from the original site and relocate the bamboo to another part of the garden or give it to friends -- noninvasive bamboo plants make good neighbors. Your neighbors might gladly welcome a clumping bamboo division, but running bamboo plants can quickly take over the entire neighborhood, so it's best to avoid giving those as gifts.
Digging Up Roots
Given the short lengths of the bamboo's spreading rhizomes, the position of the culms provide you with an accurate visual tool for determining location of the root ball. Cut the culms back to the ground with loppers or a pruning saw to make the root ball more manageable. Sterilize your pruning tools with a 10 percent solution of diluted bleach. Visualize a circle around the culms, about 2 inches from the outermost culms. This extra 2 inches compensates for any rhizomes that have spread in the soil without yet sprouting culms above ground. Cut the soil, following the circle, with a digging spade. Cut another circle about 2 inches outside the first one, and remove the soil between the two cuts. Insert a round-point shovel in the 2-inch gap, using it to pry the roots loose from the soil and remove the root ball.
After the Digging
Removal of the root ball can leave a fairly substantial hole in your yard, depending on the age and size of the bamboo clump. Inspect the hole and the surrounding soil carefully for any remaining rhizome pieces, which can sprout new bamboo shoots. Remove the small rhizome pieces before you back-fill the hole with clean topsoil. You can reuse the soil that clings to the roots, but you must pick through the soil carefully to remove any rhizomes that might break off. If you simply want to relocate the removed bamboo clump, separate the root ball into roughly four equal parts, depending on the size. Plant the divisions to the original planting depth in a site with similar sun exposure to the old spot, and water deeply to ensure transplant success.
A few rhizome pieces might remain in the soil no matter how thorough you are when sifting through the dirt. These rhizomes can potentially develop into new bamboo plants even after you remove the bulk of the clump. Monitor the area where you removed the clumping bamboo for new growth over a period of one to two months. Cut a circle around any new bamboo culms and remove them from the ground as soon as they develop. This could be as easy as pulling up the new shoots with your hands if the soil hasn't settled or if you have light, sandy soil. A garden trowel also works, if you catch the shoots before the roots spread and establish themselves in the soil.