Question
Dear Mr. Hyland,

I live about 300 feet from a fresh water lake. For years there has been a weed like plant growing in areas of my yard. My wife says they are Katelpa. I call them fresh water bamboo. They have leaves that grow up to a foot long and the plants themselves get up to 12' tall.  

I have used Round Up and other Herbicides to try and get rid of them, but even if they die I still have to dig up the root system or they will return within a few months.

I don't like using the store bought chemicals.  Is there a natural way of getting rid of them?  Either way, what would you suggest, so I don't pull my back out trying to eradicate these weeds.

Thank you.
Sincerely,
Kevin

Answer
I am not sure what "katelpa" is so I am going with the bamboo. 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; therefore, follow-up treatment with herbicides will generally be required. Few herbicides are effective on bamboo. The only treatment regime that has been proven to be effective are winter applications of diclobenil (Casoron or Barrier) combined with summer spot sprays with glyphosate (Roundup). Diclobenil 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. Recent research has shown that glyphosate (Roundup, Roundup-Pro, Glyfos, others) works better than other postemergence herbicides (such as Finale) for this purpose. However, Roundup does not translocate well to the rhizomes and bamboo will re-sprout. Reapply Roundup whenever new growth is present. It will take at least two years of this regime to attain control. In that time you will not be able to plant herbaceous ornamentals, hemlocks, or many other shrubs because diclobenil can kill these ornamental species. 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 fluazifop-p (Fusilade II, Ornamec, or Grass-B-Gon) or clethodim (Envoy). Such selective grass herbicides can be applied over the top of many broadleaf ornamentals but are not as effective as glyphosate.

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.