I made a tunnel garden; my wife is going to plant seeds in it in late Febru ary or early March. The whole thing is about 22 feet long, 4 feet wide, and 20 inches high. Hopefully, the wind won't blow this away as it did last ye ar with the much smaller, but similar in concept, hoop garden she purchased .
First, I made a row of seven hoops of flexible plastic water pipe, mounted on rebar pounded into the ground.
Then I covered it with translucent plastic sheeting, held on with the white clips shown in this picture:
The instructions said to use the cloudy, translucent sheeting as opposed to clear, transparent plastic, as it will diffuse the light better. I put the sheeting on during a sunny morning and it does let a lot of light through.
Paul