DIY Cold Frame

My most recent post got me to thinking about the home gardener and just how 'high tunnels' can be applied to the small garden. It's great that there are options for the gardeners who's livelihood depend on their crops. But, what about those of us who just want to grow some lettuce in the late fall and early winter? To that issue I say, cold frame.

Now, those of you familiar enough with Ray's Garden may notice that this particular plot looks a little alien. That's because this is not Ray's Garden. It is, in fact, The Mountainside Garden. Today's post is going to be a first. I'll be talking about the experiences of another fellow gardener. One who is much more seasoned than I am and has chosen to take on the task of building a cold frame. A task, which I have learned, is not too difficult. Even for a beginner gardener such as myself.
What is a cold frame? Why would I need one?

These are questions you may be asking yourself. Well, a cold frame is an enclosed box built low to the ground with a transparent roof. It is used as a "mini-greenhouse" and helps to protect plants from cold weather. The transparency of the roof admits sunlight and prevents heat escape through a process called convection. Hey now, don't be surprised, I payed attention to  my science teachers.

So, that covers the what. How about the why?

Simply put, a cold frame will allow the home gardener to extend their growing season much longer than with out. A cold frame along with early fall planting can stretch a growing season even into December, when the harsh winter weather has begun to set in.

Ok, anymore questions? Oh, what's that? You want to know how to build a cold frame?

It's simple! All you have to do is build a few walls to have around your frame.

As you can see, at The Mountainside garden the frame is made with three wooden boards which have been held together with a few supports. The tops have been angled so as to allow for a sloped roof. Though an angled roof isn't 100% necessary, it is better to have it angled than to have a flat roof. This will allow rain to run off the roof and not pool on top.

Important: Make the frame of your cold frame fit whatever you're using for a roof.

Roof options are numerous. Some people will just use a thick piece of plastic, others will use old window panes, and some (Mountainside included) use cheap door panels found at second hand supply stores. An old sliding door or swinging glass door makes for a great option.

Once the frame is built to the size of the transparent roof you can attach the roof with a few simple hinges (this is why an old swinging door would work well). If you can't use hinges, no problem, just anchor your roof down somehow just in case a gust of wind decides it wants to bring your cold frame with it.

There are a few final steps to getting your cold frame ready for action. First, you'll want to set up some way to prop up your roof so that you can have easy unhindered access to your plants.

 

The Mountainside Garden accomplished this by using a few small boards for support rods. They just slip them between the roof and the ground. 

Finally, you'll want to fully insulate your cold frame. Make sure it's tight all around. In the following picture you can see that this can be achieved by pushing earth to the edge of the frame.

So there you have it! A cold frame for your fall crops.



Wait! I almost forgot. Plant some veggies in the frame! What kind? Well, how about some lettuce, maybe you're in the mood for fall cabbage, kale is tasty plus very healthy, and squash is another great option. Be creative and brave. Try some bush beans or carrots. It's really up to you. Just be sure to have fun and enjoy your time in the garden.