Last year I raided a dumpster when I saw a bunch of stiff waterline thrown into it. I used them to create hoops in my raised beds to help extend the season by covering them with plastic last year. I didn’t scavenge enough to complete the project, so I purchased some 1 inch PVC to complete the project.
I drilled through them and used cable ties to connect them.
These work like mini-greenhouses when plastic is put over them in spring and fall. In the summer, a light fiberglass screen can be used to shade the plants and keep off bugs. I also use bird netting over them to protect the strawberry beds.
Note: I used vinyl deck planking for my raised beds. I put screws in every foot and left the heads up so that I could tie string off them to create a square foot grid pattern for planting.