January 6, 2011
Contact: Bud Reaves, Anne Arundel County
Have you been Bamboo-zled?
One of the most useful plants in the world, bamboo is found throughout the temperate and tropical regions of the world. A commercially important plant, bamboo is used for everything from food to flooring and is one of the most easily recognizable plants too. Bamboos are the largest members of the grass family and grow all over the world in tropical to temperate regions. There are over 1,200 species noted worldwide. One species is native to Maryland, switch cane, Arundinaria gigantea spp. tecta (photo below). It is found in wet areas in Maryland’s coastal plain and up into the Piedmont. It is considered rare in Maryland.
Bamboo grows in two forms. Clumping bamboos, as the name implies, grow in clumps; arising from a corm. Running bamboos on the other hand, grow by means of underground stems called rhizomes. The most common running varieties that are known to be invasive are: golden bamboo, Phyllostachys aurea, one of the largest that grows up to 40’ feet tall and 6” in diameter; Japanese timber bamboo, Phyllostachys bambusoides, that grow to 75’ tall; common bamboo, Bambusa vulgaris; and arrow bamboo, Pseudosasa japonica. These aggressively spreading semi-evergreen plants will take over any sunny or semi-shaded area, forming almost impenetrable thickets and effectively crowding out all native vegetation. Due to their aggressive growth habit and ability to overwhelm native habitats, running bamboos have been chosen as the January 2011, Invader of the Month.
Bamboo is an attractive plant and is very useful in many ways. The young shoots are edible and are often found in Asian cuisines. The ‘wood’ from bamboo, notably timber bamboo, is used commercially for flooring, furniture, paper, utensils, musical instruments, and in the Far East, for scaffolding. Bamboos have a unique flowering habit. They are synchronous flowerers, meaning that all populations in a given area flower at the same time. This happens every 30-150 yrs, depending on the species. As the physiological process of flowering uses so much energy, many of the plants die after flowering, their food reserves exhausted. In 2009, the native switchcane produced flowers in Maryland, which caused a lot of brown/dead-looking populations and has decreased the size of MD populations until the next generation pops up.
One of the most common uses for bamboo is for living screens as a wind and sound barrier. These are very effective but will start to outgrow the area and escape into adjacent habitats. Once it is established bamboo can spread at a rate up to 30’ feet in a year. A better alternative is to use native evergreens such as eastern red cedar, arbor vitae, or Atlantic white cedar.
Control of Bamboo:
Do not plant running bamboo. There are trees and shrubs that can be used as alternatives for screens and ornamental effects. If you must plant, then use a container or plant in an area where the roots are restricted from spreading. Controlling running varieties of bamboo is difficult at best. Root barriers that physically prevent roots from growing and spreading are not fool proof and are not easy to install. Since running bamboos spread vegetatively through underground rhizomes it is difficult to control through mowing or other mechanical means. Trying to grub out running bamboo unless it’s in very small patches is usually futile. Leaving one small piece of the rhizome in the ground is enough for the bamboo to start growing all over again. The process of grubbing the rhizomes out is also rather disruptive to the surface and will expose the disturbed soil to erosion by wind and rain. In certain jurisdictions, this type of activity will require a permit, so check with local official before attempting.
There are no known biological controls for bamboo, unless you count the Giant panda. Certain spider mites feed on bamboo leaves but they do not cause extensive damage. Pandas on the other hand, actively eat the leaves and tender shoots of bamboo, and in fact bamboo makes up 95% of their diet. Since adult pandas eat about 20-30 pounds of bamboo per day, a pair would make short work of an infested area. Pandas are however, notoriously scarce, with only about 1,000 found in the wilds of central China and another 200 or so in zoos throughout the world. So don’t look for anyone offering their services.
Bamboo, like all photosynthetic plants, is susceptible to herbicides. A very effective method for controlling bamboo is to cut the bamboo at ground level in the spring and let it grow new shoots over the summer, then in the fall spray the fresh leaves with herbicide as recommended on the label. This is repeated for several seasons until the bamboo is gone. Bamboo is semi-evergreen and has a waxy coating on the stems and leaves so a surfactant is advisable. Because bamboo is a member of the grass family, not all herbicides are effective. Selective herbicides like the growth regulators 2,4-D and Triclopyr have no effect on grasses and other monocots. In areas near the water or any wetland or aquatic habitat areas a special formulation is needed without surfactants. Check with your local forester or extension agent for specific recommendations.
For more information, please visit:
Swearingen, J., B. Slattery, K. Reshetiloff, and S. Zwicker. 2010. Plant Invaders of Mid-Atlantic Natural Areas, 4th ed. National Park Service and U.S. Fish and Wildlife Service. Washington, DC. 168pp.
For more information about Invasive Species of Concern in Maryland, visit www.mdinvasivesp.org
photos available electronically on request.