Back in 2011, I built a 24’ x 12’x 7.5’ arbor. A lot of work went into it.
I have played around with the thought of converting it into a “pole barn” type of greenhouse. Would think that a greenhouse could be built as simple or as elaborate as one wishes. Of course, it would be advantageous to do a lot of planning. I don’t know what kind a store would carry
6 mil poly.