   Growing Bamboo - February 4, 2009 Jeff Schalau, Associate Agent, Agriculture & Natural Resources University of Arizona Cooperative Extension, Yavapai County Bamboo is a long-lived, woody-stemmed perennial grass that is usually evergreen if grown in a climate to which it is adapted. The term bamboo refers to plants of the large subfamily of Bambusoideae within the family Gramineae (Poaceae). Bamboos are a diverse plant group ranging from those that grow only a few inches in height with vigorous rhizome root systems to giants of the tropics that can attain over 100 feet with trunk-like stems. Worldwide, there are approximately 87 genera and over 1,500 bamboo species. There are three reasons that I like bamboo. First, it creates a visual appeal that is cool, shady, and tropical. Second, in the slightest breeze, it has a soothing rustling sound – leaves are brushing and canes are clacking – it is a peaceful white noise that adds to the visual appeal. Third, the canes can be thinned out and trimmed up to create useful garden stakes and trellis poles. The potential for invasiveness is the primary negative attribute often linked with bamboos, but there are ways to manage its spread. Bamboo species are characterized as either “clumping” or “running”. All bamboos spread by underground stems called rhizomes. Clumping types have much shorter rhizomes causing them to spread much more slowly. Running types produce long, vigorous rhizomes that can invade adjacent areas, especially where regularly irrigated. Clumping bamboos are easier to manage in the landscape. However, running types can be contained using a root barrier constructed of either concrete or thick polyethylene material designed for that use. Root barriers should be at least 30 inches deep. Yearly maintenance and inspection is recommended. Running bamboos often find their way past the barrier material and into adjacent lawns and other regularly irrigated areas. Bamboos come in a range of heights, leaf sizes, stem diameters, and stem colors. In the Verde Valley area, we are limited to cold hardy bamboo species. Most species able to tolerate 0 degrees F are running types. One exception is the panda bamboo (Fargesia spp.): a clumping bamboo from the Himalayas that can tolerate -25 degrees F. Several running bamboos in the genus Phyllostachys can withstand winter temperatures as low as -10°. Bamboos adapted to temperate regions like the Verde Valley grow a complete set of new leaves each spring, the old ones falling away as the new ones develop. This can be viewed as messy, but the leaves are best left in place as a mulch. Bamboo is a forest plant and the natural mulch of dead leaves helps keep the soil moist and recycles nutrients. or gathered and composted if a more formal look is desired. In terms of water use, bamboo does require some irrigation to establish, but it can tolerate much less frequent irrigation once established. Like other warm season grasses, it will respond favorably to nitrogen fertilization during the growing season. Bamboo only flowers every 50 years or more, so it usually propagated by division. Plants can be harvested from established bamboo stands using the proper tools, but it can be labor intensive. It is best to transplant bamboo in the warm season. For running bamboos, use a sharpened shovel and a pair of hand pruners, dig and separate a clump that has white roots, a green top, and several joints on the rhizomes. Keep the rootball moist and replant as soon as possible. Do not leave plants lying horizontal for more than a few minutes. This will cause injury to the transplant. Do not plant running bamboos near riparian areas, irrigated fields, or other regularly irrigated areas such lawns. Running species will eventually get around the best of barriers. A bamboo lookalike, the undesirable giant reed (Arundo donax), is common around the Verde Valley and has invaded the creeks and rivers in the area. Do not transplant or encourage this plant. There are several bamboo species, both clumping and running, which would likely be successful in and around the Verde Valley. For more information about bamboo, visit the American Bamboo Society web site at americanbamboo.org. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at cottonwoodmg@yahoo.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |