SALISBURY — Bamboo can be one of the most difficult weeds to control. Unfortunately, many plant it as an ornamental or as a screen only to learn it can spread as much as 20 feet in one season. Once established, bamboo can take over landscapes, stream banks and woodlands.
Bamboo shoots can be relentless with the ability to break though asphalt and concrete driveways. Unfortunately, post emergence herbicides such as Roundup seem to only burn back the foliage, providing no real effective control.
Control of this weed requires patience and persistence. Start with physically removing as much of the rhizome and root mass as possible. For large infestations, this will require the use of power equipment. It will be impossible to remove all pieces, so follow-up treatment with herbicides will generally be required.
Few herbicides are effective on bamboo. Dr. Joe Neal, weed specialist at N.C. State University, suggests a treatment regimen that includes a winter application of pre-emergence herbicides such as Casoron (diclobenil) combined with summer spot sprays with glyphosate (Roundup). Casoron will kill many of the rhizomes and prevent others from re-establishing through early summer. After that time new sprouts will emerge and must be controlled to prevent re-establishment.
Neal notes that recent research has shown that glyphosate (Roundup and others) works better than other systemic herbicides. Unfortunately, Roundup does not translocate well to the rhizomes and bamboo will re-sprout. It is important to keep reapplying Roundup whenever new growth resumes.
Realistically, it may take up to two years or longer of this regimen to attain control. Unfortunately, during this period gardeners cannot plant herbaceous ornamentals, hemlocks and many other shrubs because diclobenil also kills ornamental species. But if the bamboo is growing in plant beds where these herbicides cannot be used, remember bamboo is a grass and can be suppressed with selective grass herbicides such as Fusilade II, Ornamec or Grass-B-Gon or Envoy. Such selective grass herbicides can be applied over the top of many broadleaf ornamentals. But these herbicides are not as effective as glyphosate products.
Another option is to put the entire infestation into turf for several years. Bamboo does not tolerate frequent mowing when the entire infestation is mowed regularly. Mowing only a portion of the infestation will suppress the bamboo, but new sprouts will continue to emerge from rhizomes, creeping into the turf from adjacent stands. Regardless of the method, an intensive effort over several years will be required to eradicate a bamboo infestation. Go to http://www.ces.ncsu.edu/chatham/ag/homehort/BambooControl.htm for more complete information.
Darrell Blackwelder is the County Extension Director with the North Carolina Cooperative Extension Service in Rowan County. Call 704-216-8970.