Last week I discussed several simple methods to help extend your gardening season. This week I explore more options for giving you a head start in the garden. These methods work equally well at season’s end with the potential to provide a year-round garden.
Insulation is the key to keeping plants safe when cold temperatures threaten. Whatever you can find to trap and retain heat will go a long way toward defying the killing conditions of frost and cold that would otherwise bring an early demise to tender heat loving-plants. Blankets, plastic, buckets and the like all can serve to add critical protection on such nights. Be sure the covering protects the foliage and that it extends all the way to the ground. This ensures that warmth from the soil is trapped, which will add a few extra degrees under cover.
A cloche is an insulating cover made for such purpose. Perhaps you’ve seen these attractive bell shaped glass covers. Dating back to the early 1600’s cloches were and still are a common and effective method of protecting tender plants and food crops. A cloche substitute that I often use is to place plastic milk jugs with the bottom cut out, over my plants. A bamboo stake or stick helps hold it in place, and the lid from the jug can be removed the next morning to allow excessive heat to escape. Plastic soda bottles work just as well. It’s a simple and inexpensive way to protect tender plants through those nights when frost and freezing temperatures are likely. A milk or soda-drinking family can amass quite a collection of cloche-like covers in no time, plus they stack up well for storage when not in use.
Cold frames are perhaps the best and most popular methods food gardeners use for insulating their plants from temperatures far lower than most plants can handle otherwise. Think of a cold frame as a mini greenhouse. The basic premise is a sturdy, insulating enclosure around the plants and a glass or plastic top or lid that allows sunlight in to heat the space. Because of its excellent heat trapping quality, all cold frames must provide that all-important way for heat to escape during the day. Cold frames can be constructed from wood, cinder blocks, hay bales and more.
A sufficiently insulated cold frame can provide an environment warm enough to allow tender plants to thrive all the way until spring, even in the harshest conditions as my friend and colleague Niki Jabbour, author of “The Year Round Vegetable Gardener” (Storey Publishing, $19.95), can attest. She gardens year round from her home in Halifax, Nova Scotia, where she harvests more than 30 different crops – even in mid-winter!
Container-grown plants offer the benefit of portability in allowing you to maneuver plants away from “Jack Frost.” Having the ability to move plants to a protected area and back again can buy you several weeks or more of extended growing time. The trick to making this work for large containers or those too heavy or cumbersome to move easily, is to place them on top of rolling platforms. I’ve seen several designs in better garden centers marketed for such purposes or you can search online. You also can easily make them yourself.
Microclimates are another technique commonly used to take advantage of pockets of warmer conditions. Think of microclimates as nothing more than small areas or unique growing environments that tend to stay a bit warmer their surrounding area. Typical reasons these areas exist is because they are often protected from wind, driving rain, frost or snow, or because they benefit from heat radiating off a building or protected area. When planted or placed near a brick or stone wall, heat absorbed and retained during the day is released at night. Plants in close proximity will benefit from this exchange. This mini environment can potentially allow plants to survive outdoors when otherwise they could not.
There is a season for everything, but it doesn’t mean you have to delay or stop gardening just because of cooler temperatures. Extending the season is an exciting and rewarding endeavor made easier by knowing a few easy-to-apply techniques.
Joe Lamp’l is the host and executive producer of Growing a Greener World on national public television, and the founder of The joe gardenerï¿½ Company, devoted to environmentally responsible gardening and sustainable outdoor living.