fixing a greenhouse without plastic?

So, I work in the garden at a montessori school and there is a hoophouse. There is not enough support holding the frame together and we get very high winds in the spring and fall, causing the hoophouse to sway and therefor stretch and now break the hoophouse plastic covering. I would love to reinforce the metal hoops and create a more stabil foundation but i'd also love to figure out a way to stop buying large sheets of plastic that eventually disintegrate in the sun, wind and end up creating such waste. Any thoughts on how to create a more sustainable covering for the hoophouse or just an entirely different way of creating a warm space for winter growing?

Thank you kindly!

The other greenhouse coverings are glass, or the transparent polycarbonate roofing panels. Both would require building a different structure than hoops. A glass house made of old single pane windows is a classic way to recycle if one can get a barn full of old windows someone saved.