“In all things of nature there is something of the marvelous.” Aristotle
Living in a climate where winters are anything but favorable to gardening can leave the lover of dirt in a state of despair… but there is hope. That hope is cold frames! They’re a relatively easy and inexpensive option that will allow you to grow some things until the temps drop below freezing consistently.
If you’d like to have fresh garden veggies well into January, using cold frames is one way you can experiment with certain crops through the winter months. Building a cold frame is not complicated when you have good instructions along with the proper tools and supplies.
Here’s a simple 5 step how-to build a cold frame!
There are two basic parts to a cold frame- the sides and top.
1. Choosing the size you’d like your cold frame needs to be determined even before location. I recommend that they be between 10″ to 12″ deep. Most garden veggies are shallow rooted and this accommodates their root systems adequately. A popular size for home garden cold frames “measure 4 to 6 feet front to back and are 8 to 12 feet long. They’re laid out with the long dimension running east to west. The frame should be just tall enough to clear the crops you plan to grow. In the standard design, the back walls 12 inches height and the front wall 8 inches high, so that there is a slight slope to the south,” according to Elliot Coleman in his book, Four Season Harvest.
2. Site location is the next decision to be made. You’ll want a sunny yet sheltered place to build your cold frame. Building alongside your home, garage or out-building is a good choice. If you choose to do this, have your cold frame on the North or South side of the building so it gets daylight all day if this is possible.
3. Once you’ve decided on site location and size it’s time to build. Your options for the sides can include just about any material- boards, concrete blocks, bales of hay, logs or you fill in the blank. If you choose lumber, I’d reinforce the corners by screwing a wood block inside each corner to the boards.
4. Next you’ll decide what your lids will be constructed from. They need to allow the light to shine in. Your options here can include old storm windows, wooden frames with plastic sheeting adhered to it or anything that will cover the top and be translucent enough to let the light shine in. I suggest making two lids for the cold frame by dividing the width in half. The lids can be hinged or just set on, but either way I’d personally recommend putting weights on each of the four corners to prevent them from flying off in high winds. If you decide to use the wood frame with plastic, cut the plastic 4″ larger on each side than the lid frame. This will allow you to roll it over the frame and staple it with a staple gun. Make sure the plastic is taught when you’re done stapling so they will not flap when windy.
5. Now you get to fill your cold frame with the growing medium. I would layer the bed in this fashion, bottom up order: manure, straw or grass clippings, leaves and then top with a rich, organic compost or soil. Be sure to leave enough space for the crops to grow without bumping the lid. See step 1.
Building a cold frame will give you such satisfaction as you are able to harvest garden fresh veggies well into the cold days of winter. I’ll touch base next time on what things you can grow in your cold frames.
I would highly recommend Eliot Coleman’s “Four-Season Harvest” book for further reading. There are many styles to choose from starting with a simple straw bale structure to an elaborate glass pained wooden structure with hinges. Coleman’s book is extremely detailed and is an excellent resource that I turn to often.