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.
In the long beds I often use a piece of cattle or hog panel in the middle to provide climbing area for peas and other plants that can go up. Those long ones aren’t nearly as sturdy as the hoops in the 4 x 4 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.