Three types of barriers to plant root growth were investigated. Previously, a long-term barrier was created by placing loose rock between buried waste and topsoil; this barrier successfully prevented plant root and animal intrusions into buried waste. Then an intermediate-term barrier was made by encapsulating phytotoxin into a polymer. The polymer regulated phytotoxin release and also acted to prolong the toxin’s effectiveness. A short-term barrier was made by spraying phytotoxin directly onto a thin layer of soil between the waste and topsoil. Trifluralin proved to be the most effective of seven phytotoxins studied because it prevented root penetration of the barrier. Trifluralin is not translocatable and allows nonaffected plant parts to grow normally.