Raised Beds – Preventing Tree Root Infiltration

Q: I have a raised bed tomato garden that has been taken over by tree roots. What do you recommend I do to prevent this from happening year after year?

A: I have the same problem in my flower beds. For the annual flower beds I just tear out the roots since I’m replanting the bed every year. For the perennial beds, I water a little more often in drought and hope the tree roots don’t affect the plants too much. One option is to install a root barrier outside your bed. A sheet of aluminum flashing or fiberglass will work but it has to be buried edgewise 18″ deep to thwart nearby tree roots.