Bamboo species are gaining in popularity for backyard landscapes due to their variety, quick growth and graceful form. A true grass, bamboo sizes range from inches-tall groundcovers to giants that can easily screen a second-story window. Some varieties are cold-hardy and make wonderful additions to northern gardens. As familiarity with bamboo grows, gardeners will find bamboo to be a valuable plant for both beauty and hardiness.
Bamboos have few pests and do well with average-to-good soil and regular watering. They are resilient plants. In fact, unlike most container-grown plants, a root-bound bamboo will often spread more quickly than a bamboo with plenty of room in its original pot. Prepare the planting site with a root barrier and by amending the soil, if necessary. Like other grasses, bamboo will respond to a high-nitrogen fertilizer with rapid growth, but extra fertilization is not required if the soil is adequate. Running bamboos do well in sunny areas. On the other hand, clumping bamboos are understory plants and do best in partial shade.
When a specific species of bamboo blooms, often every individual plant of that species will bloom at the same time. This is called gregarious flowering. No matter where the separate plants may be located, even on another continent, they will produce flowers simultaneously. After the parent plant has flowered, it will often decline in health and die. Fortunately, a bamboo plant may flower over two or more years, and the seedlings may be growing before the parent plant dies. The flowers themselves are not showy, resembling the flowers of any other grass, but do have various forms that allow botanists to categorize the species. Finding a bamboo in flower can be difficult. Phyllostachys bambusoides only flowers every 120 years. Not all bamboo species are gregarious bloomers, however. Research the variety before planting.
A running bamboo spreads quickly by underground rhizomes. Like Bermuda grass or other running lawn grasses, this creates quick results but also creates an invasive nightmare if the plant is not properly controlled. These rhizomes are usually quite shallow, often a foot or less deep in the soil. A metal or polyethylene root barrier, two feet in depth, will prevent most rhizomes from escaping into the surrounding yard. Many running bamboos can be controlled with simply mowing over new shoots or root pruning, in a trench, around the plant. Planting a running bamboo can be risky for a casual gardener, as this tenacious bamboo can send new rhizomes out roughly the length of the tallest culm. Following this rule of thumb, a bamboo with a culm 10 feet tall may also have sprouts 10 feet away from the parent plant. However, for erosion control or much-needed privacy over a large area, running bamboos are both effective and eye-catching.
A clumping bamboo expands slowly through thick rhizomes. These thick, tuber-like rhizomes only grow a short distance, even a few inches, from the parent plant before sprouting. The culms of a clumping bamboo are usually thinner than those of a running bamboo, and a clumping bamboo will form a dense screen in contrast to running bamboo's tendency to form an airier grove. These habits make a clumping bamboo a better choice for a casual yard, and their graceful form can anchor a mixed privacy planting or be an elegant focal point.
Umbrella bamboo (Fargesia murielae) is recommended by Susanne Lucas of the American Bamboo Society as a hardy, non-invasive clumping bamboo, able to grow in USDA zone 5. It will grow to 12 feet tall and thrives in shady areas. Marbled or dwarf black bamboo (Chimonobambusa marmorea) is labeled as a “first-class hedge plant,” growing two to six feet tall, by the Sunset Western Garden book. This is a running variety and should be appropriately controlled. Golden Goddess bamboo (Bambusa multiplex 'Golden Goddess) is a clumping variety that reaches fence height, as is the slightly taller Alphonse Karr bamboo (B. m. Alphonse Karr). Both of these popular varieties are hardy to 15 degrees F, and Alphonse Karr has bright green or yellow stripes on the culms.