Ask the Master Gardeners: Large pots are best choice to contain running bamboo

By: Laurie Meyerpeter Placer County Master Gardener
-A +A
Question: I have a black bamboo that is too large for the pot. How and when should I divide it? Answer: Black bamboo is a running bamboo so it is wise to grow it in a container or use a bamboo barrier product if grown in the garden. Mature running bamboos can be aggressive plants, invading neighboring lawns and flower beds in time and may be difficult to remove. Bamboo grown in pots will not grow to the massive heights that it will in the ground, nor will the canes be as large in diameter, which is probably a good thing since many bamboos are quite large! Bamboo does best in a large pot. If bamboo outgrows its pot, it can be repotted into an even larger container or divided into two plants and planted into two different pots. Late winter is the best time to divide running bamboos. Tip the pot on its side and remove the bamboo from the container. Using an ax, loppers, or saw, cut and hack the root mass into two sections. Bamboo plants can be heavy and the rhizomes tough so this can be hard work. Having an assistant is nice for large plants. Although bamboo can be divided into smaller and more numerous sections, dividing in half is safest for the novice gardener. Repot into two large pots using a product clearly labeled “potting soil.” Water immediately after planting. Water and fertilize bamboo regularly throughout the year. Any fertilizer applied according to package directions is suitable, including organics, but a slow-release formula is a good choice for the novice. Follow the instructions on the label. Over time, some old canes will die as the bamboo sends out new canes as replacements. Prune the old canes out using pruning shears or loppers. If considering bamboo for a small backyard garden, clumping bamboos are available. These plants are not aggressive, spread slowly outward in a circular pattern, and containment is not necessary. Most are hardy to the low 20s and into the teens depending upon variety. For detailed information on bamboo, try The American Bamboo Society Web site at In addition, there are several nurseries in the foothills that specialize in bamboo. Have gardening questions? Call the Master Gardener hotline at (530) 889-7388.