Winter Greenhouses: Providing a Harvest in the Off-Season

“You don’t need to wait until Spring to grow your own food. Here’s how I built a DIY greenhouse so I can grow food, even in the snow. First, I staked out the corners with rebar and leaned my wood baseboards against those stakes. The cattle panel is bent to make the roof. But the best part is these panels stay put with just tension from the rebar. But the key to keeping things warm even when it’s zero degrees outside is in the layering. I covered the cattle panel with thick greenhouse plastic to protect my plants and trap heat from the sun and added a second layer of row cover to keep my soil from freezing.”

“This greenhouse uses passive solar to trap enough heat from the sun to keep the soil from freezing. Now that doesn’t mean we can grow tropical plants inside. But there’s tons of cold hardy crops that can survive the temps that we see inside of this greenhouse. The concept for this greenhouse was based on Elliot Coleman’s book The Winter Harvest Handbook. And I definitely recommend - if you are interested in growing all year long in a cold season climate like mine – grabbing a copy of that book.

And just in case you thought I would be super limited in what types of plants, I could actually successfully grow in this greenhouse all winter long, you’d be wrong. I have about 20 different types of plants in here, and they’re not just greens.”

Chad uses straw and wood chips to insulate his greenhouse and to provide thermal mass. Large vats of water and concrete or stone pavers are other effective ways to provide passive heating for your greenhouse. The water or concrete absorbs the heat of the Sun during the day and then releases it at night – keeping the greenhouse warm and cozy.

A winter greenhouse can be as simple or elaborate as you want it to be. It just depends on your ingenuity, willingness to do research, and capacity for hard work. Many ways exist to do it inexpensively. At the end of the season, you can ask your local nursery if they have used greenhouse plastic that they are throwing away or selling cheaply. Old windows can be used to build a greenhouse. Even sheets of clear rigid plastic can meet your needs.