April 24, 2011

Cold frames extend season

We've all seen how completely unpredictable North Country weather can be. Temperatures often fluctuate wildly and conditions change radically from day to day or week to week, sometimes even from hour to hour.

That lack of predictability can often mean big problems for area gardeners looking for ways to extend what is a very limited gardening season. Wouldn't it be nice to be able to start seedlings or put plants out in late April or early May without having to worry about frost or snow? You can.

Cold frames offer an easy, effective way to protect plants, and extend the gardening season by as much as three months. By using cold frames, North Country gardeners can start planting up to 45 days before they would otherwise be able to, and they can keep plants growing up to 45 days longer at the end of the season. With cold frames, gardeners can grow early (or late) crops of cool weather and salad vegetables, such as lettuce, spinach, radishes and cauliflower, even while there is snow on the ground.

What are cold frames? Simply put, cold frames are just inexpensive miniature greenhouses that can be used for starting and protecting frost-sensitive plants.

The idea is a very simple one. Take the energy from the sun and use it to warm the soil and the air within a contained area in order to create the right conditions for growing happy, healthy plants out of season.

The sun's heat is transmitted through the lid of the cold frame and stored in the soil floor. The cold frame then contains that heat and slows heat loss from the ground during the night. On particularly cold nights, additional insulation, such as old blankets, can be used for added protection. If desired, a supplemental heat source can be placed inside the unit. Almost any size cold frame can be easily heated with a small electric heater.

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