Make this plant pole for under $20 in about an hour. It uses less than 2 feet of floor space in your greenhouse. It holds small to medium-sized pots (herbs, seedlings, etc.). Great for on the patio too. As an added bonus, a light can be hung at the top, which will be handy when you absolutely must go to the greenhouse after dark :) Feeling really creative? Paint and decorate the pole.
Mylar blankets and a 65-watt incandescent lightbulb kept my greenhouse 11 degrees warmer.
Built with cement block, cement glue in a tube, and leftover granite countertop.