Running bamboo varieties spread quickly through rhizomes that grow shoots several feet from the parent plant. To keep your running bamboo from growing into unwanted areas, choose one of these two solutions to stop the spread of the rhizomes.
Install a Barrier
Create an underground barrier by sinking a thick plastic sheet about 30 inches deep into the ground. Place the barrier where you want the bamboo to stop spreading. Keep a couple inches above ground so the roots won't spread on top of the soil. Inspect the barrier for any defaults before using. If the barrier has any cracks the roots will grow through them.
Dig a Ditch
Dig a ditch around the bamboo plants about 3 feet deep and wide. As the roots enter the ditch, cut them out. For aesthetic purposes, fill the ditch in with mulch. Find the roots by poking around in the mulch with a pole to find roots. Cut the roots out with shears and discard. Check for root growth on a regular basis.
Enjoy the unique beauty of bamboo without losing control of their quick, sporadic growth pattern!