We grow the Juniper in lava-rock (pumice stone) by boring a hole in the rock and sawing flat the bottom of the stone. Since the lava-rock is porous the rock serves the same purpose as the bonsai pot. When we think of a traditional bonsai and what it should look like, we think of a Juniper Procumbens. They are hardy and long-lived and tolerate many adverse conditions. Popular and unique.