Cedar Sawdust – Plant Growth

Q: I’m a woodworker and have lots of sawdust. Last spring I put a layer of cedar sawdust on my vegetable garden. I was not happy with the plant growth I got. Is there something in the cedar that inhibited growth?

A: I don’t think cedar sawdust would inhibit plant growth. On the other hand, it probably would inhibit seed germination like most tree sap extracts do. That said, sawdust of any kind can get wet and then be slow to dry, which would inhibit the soil drying like it ought between rains. I’d use an inch-thick layer of sawdust or shavings under landscape shrubs but not under flowers or vegetables.