A good solution it seems.
Here are the simple ways I have tried for my raised beds:
Use a sledge hammer to drive rebar into the ground at all 4 corners. Take two equal lengths of PVC pipe length depending on how tall you want the structure.
Put the pipe over the rebar and push it into the ground(the wooden frame around the garden helps to stabilize it) at diaganol corners. Tie the intersections together with strong rope. Cover with plastic attached to poles and anchored by heavy firewood for green house effect.
For shade use a fence or rebar and pvc or leftover metal pipes on one side of the bed. You will have two vertical pipes over the rebar. Attach the pipes with a horizontal pipe and elbows attached to the vertical.
From these you can hang cattle panel or netting for vines to climb. You can also use a shade cloth attached at the top and brought forward lean-to style and anchored by tent stakes for shade from the sun during the hottest part of the day.
diaganol = diagonal
brain ain’t workin real well transposing like crazy lately.