Hi Future Stringer Queen Iza 😄

They're wood. The off-ground ones are recycled wood and the on-ground one is treated wood...they're lined with plastic I think.

My local nursery sells the off-ground ones for $150.00 and they're about half the size of the ones I'm getting, so mine are a bargain at $80.00 each,,,and $150.00 for the big one.

I can't wait!