Is it effective to dig down and place a board in the ground to contain the runner of Russian Sage? Love it but it's taking over. I read what you have to say to someone else about less water and no fertilizer.
Denver County Colorado
To find the most appropriate individual to answer your question, what county in Colorado do you reside? Thanks! Ruth
I'm in SW Denver
A physical barrier might work if the barrier is deep enough to prevent the roots from sneaking underneath.
There is a plastic product used to control bamboo (generically called 'bamboo barrier') that you might consider. It's a thick polyethylene and, being plastic, won't rot when it is in contact with soil.