Over my kid’s spring break, we did a lot of little projects to start gearing up for this year’s vegetable gardening. Most of these were pretty much housekeeping. Pulling out and burning all last year’s vegetation, bit of soil prep and the like. The one project I am most pleased with is the construction of a cold frame.
This has been one of my “Back Burner” projects for a long time. I have been intending to build several of these for the last couple years, and the plan has been to have them done by fall so I could grow some cold hardy crops in them through the winter. But as things go, they have never materialized as planned. Until now.
What, exactly, is a cold frame you may ask? The best description that I have heard of the cold frame is that it is a bottomless box with a skylight. If you can envision that, you have a pretty good idea of what one should look like. The one thing I would add is that the top, or “Skylight” Is sloped, higher at the back than at the front and for best results it should be facing south to get the most possible exposure to the sun.
A cold frame is essentially a miniature green house, and properly built and located, it can dramatically extend your growing season. In fact, in many of the climates found on the North American Continent, a good cold frame can provide you with a nice little garden salad all winter long. The key to your success is to start the process with cold hardy crops. Spinach, leeks, scallions, carrots, onions, broccoli and a wide variety of greens are all excellent choices for cold frame gardening.
One out of the ordinary salad veggie that does well in cold frames is miner’s lettuce. This leafy green got its name back in the California gold rush; it was the only salad in town for many 49ers out on their claims. It can be found naturally from southern Alaska to Central America. It resembles spinach in taste, is an excellent source of vitamin C. Miner’s lettuce will thrive in your cold frames throughout the winter months.
One of my favorites, having been an adopted son of the south for almost two decades, is the humble collard green, some will disagree, but I love these greens boiled with some vinegar and sugar and a couple slices of bacon.
In addition to growing a salad garden in the winter months, cold frames are a great place to get seeds started early for spring planting. After the kids helped me build our cold frame, they couldn’t wait to get some seeds going, and now we have watermelon and sunflowers happily germinating a month earlier than we could with an unprotected outdoor planting. So, my timing for construction turns out to be not quite as seasonally inappropriate as it at first seems (OK, I should have built it last fall, but I didn’t, so…better late than never!)
Cold frames are simple, cost effective, and easy to build. Around my place, the best projects always begin with a scavenger hunt! More often than not I can find at least some of my materials in the leftovers that seem to accumulate around any homestead. The materials list for a cold frame is a pretty short one, you need lumber to build the box, something to serve as the cover/skylight, and hardware to put it all together.