Which Plastics Are Safe For Gardening? - Epic Gardening Dec 3, 2014 . For this reason, try to stay away from PVC setups in your gardens. I know it's attractive to have a cheap PVC garden, but if you value your health, choose an alternative plastic. *Note: not all type 3 plastics use phthalates as a plasticizer, so you may be OK using some PVC products but be sure you know..