Q: This showed up in one of my beds this spring. Can you identify it? We had some black bamboo nearby but we thought we had it contained. It was set in a pot that was inside a larger pot.

Could it have “jumped” over the lip of both pots? Any recommendations on how to stop this stuff?

A: Your identification is correct. It’s a bamboo culm (sprout). My guess is that a root grew through the bottom of the pots aboveground…but it could also have escaped over the rims if the pots were buried.

I recommend persistent chopping of culms whenever seen, certainly before they get twelve inches high. You’ll gradually see the number of culms diminish as you starve the plant.

You can spray glyphosate (Roundup, etc) on the culms but control won’t be much faster.