But don't you want it to breathe and get air? Just center that plexiglass and you should be good to go. Wouldn't you be worried about overheating otherwise? Its gonna get hot under there.

-Babka

At our old house i usually kept it completely covered until most had sprouted then i would lift the glass up with bricks on all four corners. Can't use the real glass panes now because of three rambunctious dogs. They did their part to help in the move lol

turn it 90 degrees.. and see if you can cut it into two halves that do fit...

ken

You can always place wooden crossbars across the expanse in say..two or three places then place plexiglass on top of them...

Ken thank you for my duh moment. We can just screw the side piece off and trim the ends to fit the plexiglass! I was ready to go to the hardware store and pay 69.99 for a bigger sheet! Thank you :o)