I didn't believe my eyes when I went into home depot looking to buy seed starting mix! Miniature greenhouses! the biggest one, which you could walk into and was about 5'X5', was a hundred dollars! It was big enough for four to six small flats of plants depending on how you spaced your shelves! I couldn't believe the price! and the smallest thirty dollar one was big enough to house one flat of plants and could easily sit on a picnic table outside somewhere - Seriously! they had some kind of sturdy fiberglass frame and the usual plastic sheeting covering. I am thinking of getting one next year! If you have a Home Depot near you and you want a small greenhouse I think this would be the perfect first greenhouse for someone who has never had one before!!!