Glyphosate should work with cut bamboo culms (stems, canes) by painting it onto the cut end within five minutes after cutting. We do not have research about using triclopyr for this purpose. You would need to verify the mention of this application of any herbicide on its product label, as specific instructions and allowances will depend on product formulation, even if the active ingredient is the same. In either case, treatment of only a few cut culms will not kill the colony, and may not even slow its spread by very much. Early autumn is probably the best time make treatments on cut culms.

If the bamboo colony is entirely on your property (that is, if it does not belong to a neighbor), then we suggest you have it removed entirely. This is no small undertaking, we realize, but it will give you the best long-term solution if its rhizomes can be dug out with machinery. Otherwise, consider having a rhizome barrier (sold by various entities online) installed either surrounding the colony entirely or used on any side you want to stop its spread. This involves digging a trench, usually with machinery, and buying a roll of specialty plastic barrier that keeps its rhizomes from re-invading the yard each year.

There are ways to slow its spread with less effort and expense, but it takes vigilance and routine monitoring so culms do not spread unnoticed. The primary time new culms appear and need removal is March through May, when they are also still tender enough to easily be cut or broken off.

You mention some areas are difficult to access, so perhaps hired help would make the task easier. Since repeat access to such areas to keep removing culms is not practical, instead, you could consider having help in cutting-down and herbicide-treating all of the culms. This avoids the use of heavy equipment that may not be able to access the whole colony for removal without risking damage to other plants or structures. Repeat treatments of re-sprouts are likely, but over time as the colony weakens this will become less and less of an issue until it finally succumbs.

You can check back with our website soon in upcoming weeks for a new page we are preparing on bamboo control. More details will be given there for each control tactic.

Miri