My friends started this company, it's called Tunnel Gardens. These portable tunnels fit over your garden, require no additional heating, very little water and grow plants beautifully all winter long. Here is a short 1 minute video showing you their garden last winter.
Here is their website if you are interested in ordering a tunnel for your garden at home. The pricing is extremely reasonable, they have several different sizes available, and they ship right to you. Please take a moment to check them out, if you are a gardener like me it will be well worth your time!
Happy Gardening Everyone!