I am designing/building a removable lean-to greenhouse to gain may be more than a month's growing time in Zone 6/7. I hope to put my plants in ground 4/15. In my area I think normally it should be 5/15.
Because I don't have the room, the greenhouse will be in the same space as the final patch, so it has to be removable once the plant get to be may be 30" tall.
Once complete, I think the greenhouse can be installed and dis-assembled in less than 15 minutes and be stored away in very little room.
dcarch