How Fast Does Black Running Bamboo Grow in Pots?

Running Black Bamboo

• Running black bamboo grows 15 feet tall but judicious pruning keeps shorter indoors. New stems are green but turn bright, shiny black within six to 12 months. If the leaves don't naturally fall off, removing them from the lower one-third to one-half of the stems highlights the coloration. Black running bamboo is native to China but is naturalized in Hawaii. It's hardy to minus 10 degrees F, or U.S. Department of Agriculture plant hardiness zone 6, although in containers it shouldn't be left outdoors north of zone 7.

Growth Rate

• Few plants grow faster than running bamboos. These grasses extend long rhizomes, modified stems that grow just under the soil's surface. New stems, called culms, sprout along the continuously growing rhizome just behind the tip. Running bamboos grow up to 30 feet every year. Even though running black bamboo spreads at a somewhat slower rate, expect to replant your potted bamboo every year.

Bamboo Houseplants

• Plant running black bamboo in a container at least 4 inches wider than the existing rootball. Bamboos need moist but not soggy soil, so ensure the pot has adequate drainage. Use well-draining potting soil and feed the bamboo with a high-nitrogen fertilizer, such as 30-10-10. Running black bamboo needs protection from the hot afternoon sun, so site the container in light shade. If necessary, shorten the culms by cutting them just above a branch. Once the bamboo roots completely fill the pot, either move the plant into a larger container or root-prune the plant and repot it back into its existing container with new soil.

The Bottom Line

• Running black bamboos make dramatic container plants. Give them large containers and expect to repot them into larger pots every year. Alternatively, knock them out of their pots yearly, prune back the rootball and then repot them back into their existing container.