For those of you who want to get a jump on the growing season but don't have much room, the 4 Tier Mini Greenhouse is the perfect solution. It comes with all the pieces and a plastic cover so you can have your plants in front of the window in a controlled environment.
I have used the 4 Tier Mini Greenhouse for more than just starting bedding plants. When I was short on space, I also used it for my houseplants. I do have to say anything tall does not fit too well on anything but the top shelf. I had my fig tree, banana tree and a couple others on the top shelf and spider plants, Devil's ivy and African violets on the lower shelves. I did not use the plastic cover when my house plants were on it, as it would have been too hot and humid for a few of them. I'm sure the fig and banana trees would have thrived, but the African violets not so much.
It is also a space saving shelving unit for in a larger greenhouse. It does come with casters so it is semi-mobile, but I do suggest you be careful when moving it (especially if it is full of plants). I assembled mine a few days ago and when I moved it I lifted too much and had it come apart; would not have been good if it was full of plants.
It is quite versatile and I do recommend anyone who needs extra shelving for plants to get one. If using all four shelves for bedding plants remember to rotate them every couple of days so they receive proper light, especially if the window isn't right to the floor. Also, try to avoid heavy items on the top shelves as it may become top-heavy and tip over; not something anyone wants to happen.
Enjoy your 4 Tier Mini Greenhouse! Mine will be on my deck housing my bedding plants when I get them.