Growth Rate of Bamboos
Bamboos are the fastest-growing plants in the world. A member of the grass family, the bamboo grows by filling individual cells with water. It doesn’t have to build cell walls as other plants do, but simply expands them. Among the larger timber bamboos, growth rates of about three feet in height per day are not unusual. In addition to growing up, bamboos also grow out.
Promoting Growth in Bamboo
While the care you give it can certainly improve bamboo’s growth rate, you should be careful. Running bamboos can quickly become an invasive nuisance if you over-fertilize. Bamboo is basically a large grass plant, so high nitrogen fertilizer will have the same effect as if you fertilize your lawn. Watering properly also promotes growth.
Restricting Growth in Bamboo
In most cases, you’re more likely to be trying to restrict the growth or your bamboo than encourage it. To do so:
- Prune culms (stems) at ground level or higher; culms will not grow back.
- Give it basic care but don’t overdo fertilizer.
- Restrict the roots of running bamboo.
Small bamboo varieties are the sort used as edging or ground covers. Most of these will grow no more than four feet tall. Sasaella ramosa is a ground cover version that will grow from 18 inches to three feet. It is hardy in USDA Zones 7 through 9. Pleioblastus pygmaeus, or pygmy bamboo, rarely tops two feet. It grows in USDA Zones 6b to 10.
Mid-sized bamboos make good screens and living fences. Fargesia bamboos are a group of cold-tolerant clumping bamboos that will grow almost anywhere in the US except very hot, humid areas. They range from eight to 16 feet in height. Phyllostachys are running bamboos, and many can be grown anywhere in the US. Mature height ranges from 15 to 30 feet, depending on the variety.
Timber bamboos are the tallest of this group of plants. They include plants from the Phyllostachys group that can reach 50 feet when mature. Bambusa oldhamii, commonly called Oldham’s bamboo or giant timber bamboo, grows to 65 feet. Native to Taiwan, it grows well in areas like California and the southern states. The tallest bamboo in the world is the tropical Burma native Dendrocalamus giganteus, which can reach over 100 feet.