The price on landscape timbers has finally dropped, so I'm getting ready to build my new raised hop beds. I'll prep everything this summer, and transplant late winter before they come out of dormancy.
How deep will rhizomes go before tunneling under an obstacle and popping up on the other side?
I know the roots can grow very deep, but the rhizomes typically grow horizontally near the surface. I want to lay enough courses of timber to fully contain each plant, but don't want to waste money, effort and soil installing extra courses that aren't necessary. I'm guessing that when they hit an obstacle, most of the time they'll turn towards the surface. I just don't want to deal with the ones that head down instead, then pop up in the middle of my yard a year later.