A barrier for deterring slugs, snails, and other gastropod mollusks from entering an area, and a method for using the same are provided. The barrier includes an elongate tubular support having a plastically deformable core member and an outer sheath. A plurality of outwardly extending projections are attached to the tubular support. Means for fixing the position of the barrier may also be provided. A planter having an integrated mollusk barrier is also provided.