Cold frame gardening is a simple way to extend your harvest season, allowing for fresh crops year-round. The structure consists of a bottomless box that sits on the soil and a glass "light".
Construction is easy--the cold frame can be made using salvaged wood and old storm windows.
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Step 1: Gather Materials
- Find a light. In this case, we used an old storm window measuring approximately 70'' x 26''. The light should not exceed 4' in width, to make harvesting an easy reach.
- Find scrap wood that will fit your light.
Note that the frame can be made of other materials such as concrete blocks, straw bales, etc.
Tools and Hardware you will need:
- Saw (handsaw would work, but we used a circular)
- Measuring Tape
- Builder's square
- Hinges (we used a 4" strap hinge)
- Something to prop the light open to harvest and vent (we used a curtain rod)
Step 2: Measure and Cut
- Measure the exact dimensions of your light.
- Measure and mark the wood to fit your light exactly.
- The frame should slope towards the south (for maximum solar gain in the winter). Therefore, the back of the frame should be at least 4" higher than the front.
- Cut and label your pieces. Remember that the two sides should have an angled top.
Step 3: Assembly of Frame
- With all of the pieces laid out, begin to screw them together.
- Use a square and corner brackets to make sure the pieces meet at right angles.
- Reinforce corners with nails for added stability.
Step 4: Attach the Light
- Place light on top of frame, making sure that it fits to perfection.
- Attach the light with several heavy-duty hinges, spaced evenly.
Step 5: Finishing Touches
- Add handles to the sides of the frame for easy transport.
- Add additional handle on light (if necessary) for trouble-free opening and closing.
- Add prop for ventilation and simple harvesting. This can be a hydraulic arm, stick, or, in our case, a curtain rod. Ideally, the prop should serve multiple heights.
Step 6: Put It to Use
- Find a good, sunny location for your cold frame.
- Prepare the soil and get to planting!
Here are some suggestions for winter cold frame crops:
- Swiss Chard
Remember, crops vary depending upon your location (and the amount of sunlight you get in the winter months.)
We would like to credit the book "Four-Season Harvest" by Eliot Coleman for being a wonderful and informative reference.