Winter Vegetables Sprout in a Cold Frame

During the doldrums of February, the avid gardener takes a turn through the greenhouse at the local nursery. Ever wonder how they cultivate all those varieties in the dead of winter? It's no secret! You can create a mini-greenhouse in your backyard with a cold frame, says Victoria Elder in The Journal Newspapers.

The idea behind a greenhouse is to create warm and moist conditions that will promote germination and growth. The cold frame has the same effect of concentrating warmth and moisture, albeit on a smaller scale. It's not difficult to build. Now is the time to build one as the days get longer in February. A minimum of eight hours of sunlight typically provides enough to get your favorite vegetables started.

Start charting your design on paper. Remember, don't get greedy and try to make it too big. The frame must be light enough to remove and store away after harvesting your mini-crop to make room for the regular springtime planting. Go to a lumber yard and choose durable wood that's both rot and pest-resistant. Generally, you'll want to stay away from most pressure-treated woods with chemicals that can leach into the soil and your plants. You don't want to serve mustard greens laced with arsenic. Go with a safer material such as untreated cedar and add a coat of latex primer and paint. Construct the panels from glass, Plexiglass or clear plastic.

The easiest and cheapest design involves converting an old screen door. Build a rectangular frame, take a glass door (with the glass still intact) and attach it to the frame using hinges. That allows for easy opening, an important feature whenever outdoor temperatures get above freezing--you don't want things to get too steamy and suffocating inside. That's when you'll need to ventilate your cold frame briefly to let oxygen reach your plants. Or simply let the door rest on the frame and provide some way of propping it open. Buy a small thermometer so you can monitor the temperature inside.

It may sound like a no-brainer but remember that you need to prepare the soil prior to installing your cold frame. It should rest at an angle in an area that gets the most sunlight. Choose plant varieties that mature quickly, preferably within 30-45 days. These might include mustard greens, lettuce, spinach, radishes, chives, spring onions or parsley. Mixing in marigolds is a way of discouraging pests and providing a dash of color at the same time. Soon you'll be the first on your block to enjoy a fresh, homegrown salad.