Cold Framing in the Median

It's time for the next chapter in the life of my median garden! Just this weekend, the garden transitioned into winter mode with our modification of the white picket fence into a cold frame. Since I have been taking Cindy Conner's classes at J. Sargeant Reynolds, I have become increasingly interested in season extension and gardening through the winter. I've been using the book Four Season Harvest by Elliot Coleman as a guide to transitioning this garden into one that produces greens all the way through the winter months.

A few weeks ago, we ripped out the summer vegetables -- peppers, tomatoes, a gourd vine (originally thought to be winter squash!) and transplanted in a variety of greens we had started from seed. I ordered a lot of my seeds through Seeds of Change, a great seed catalog that offers organic, open pollinated seeds. Currently growing are collards, arugula, Osaka Purple mustard greens (rumored to be extremely spicy!), spinach, mesclun mix and purslane (some people accuse purslane of being a weed but it's edible).

A key element in season extension is the construction and use of cold frames. These are essentially miniature greenhouses placed on top of a vegetable bed that provide a more stable internal environment for cool-season plants. Mediating the effects of temperature variations and wind helps the plants grow and stay alive. The addition of a cold frame can up your garden climate to Zone 8 or 9 (we're in 7 here in VA), meaning you can plant things later and they'll grow and last much longer!

To make our cold frame, we made three 'boxes' cut to fit on top of the fence so that they rest on the fence slats. We stretched plastic over the boxes, using staples to attach it around the edges. There are also bracer sections of wood screwed in at the corners to hold the box square and provide further attachment points for the plastic, which does dip down in the middle a bit. These cold frame tops fit on top of the fence fairly well, though the fence is certainly not square, meaning that there are some uneven edges. We also stapled plastic to the outside of the fence, using a limited number of staples so it's easy to remove next year. We will also make a device to prop open the boxes to allow air flow on warmer days, though we haven't done that yet...

Greens are growing inside!

There are lots of options for designing cold frames in your own garden. Some people make solid wooden boxes with glass tops; another option is row cover held up with hoops made of metal or PVC. There are a lot of great resources on the internet for learning how to build one. Check out this video:



One thing to remember is that the inside of the cold frame will still be cold. Greens don't mind the cold at all, and often are much tastier and sweeter after the first frost. The key is to provide a protected environment so the plants aren't battered by harsh storms, winds or even snow, and a more gradual transition as the temperature warms and cools throughout the day.

Hopefully I'll get back to you soon with a post on the harvest from this garden! Will we be eating salad all the way through spring? Stay tuned...