Gardener: Extending your growing season
Take steps to protect cold-sensitive plants.
Scripps Howard News Service
Many parts of the country will soon be experiencing frost and freezing temperatures, which can threaten the survival of your warm-season vegetable plants. By keeping frost off the leaves or keeping the temperature around the plants even a few degrees warmer, cold-sensitive plants may survive and continue to produce a little longer.
One technique I use is to apply a thick layer of organic mulch around the base of all my plants. Not only does it keep the roots warmer, it also helps to maintain the soil temperatures at a more even level and can reduce the chances of the ground freezing or heaving.
Physical barriers are another effective way to retain and capture a few extra degrees of heat while keeping season-ending frost off plants. Commonly referred to as floating row covers, the material is typically made of a lightweight spun-bound or nylon material. In some cases, the material is so light that it can actually be laid directly on the plants, so that it appears to float. In virtually all cases, I prefer to support my row cover with metal wire or flexible PVC plastic piping stuck into the garden beds. The row cover material is placed over the frame a few inches to a foot above the plants. It is then pulled tightly and secured around all the edges with bricks, soil or whatever you may have that is convenient and sturdy enough to hold.
The row-cover material is designed to allow light, water and air in but provide a protective barrier from frost and pests. When the sides are secured around the bed completely, several extra degrees of warmth can be retained and could make the difference in survival for marginally hardy plants.
When time and energy permit, container-grown plants offer the maximum in portability in allowing you to maneuver plants away from Jack Frost. Having the ability to move plants from the frigid outdoors to a protected shelter and back again can buy you several weeks or more of extended growing time.
Another trick I use is to look for the most protected, sunny area for planting. Referred to as "microclimates"because of their small, unique growing environments, these are areas protected from wind, driving rain, frost or snow. This mini-environment can allow plants to survive outdoors when otherwise they might easily succumb to a killing frost or other harsh conditions.
Cold frames are another technique for providing added protection in the early spring or late fall, and potentially year-round. Think of a cold frame as a mini-greenhouse. The basic premise is a solid, insulating barrier around the plants and a glass or plastic top that allows sunlight and heat in. Cold frames can be constructed from wood, cinder blocks, hay bales and more.
You can plant directly into the soil within the cold frame or place seed flats or containers inside. A sufficiently insulated cold frame can temporarily extend the growing season and it can even provide an environment warm enough to allow tender plants to thrive all the way until spring. However, with the exception of row covers, whenever an enclosure is placed over your plant(s) at night, be sure to remove it the following morning or at least provide a way for the heat to escape. The insulating effects of a plastic or glass cover can have devastating consequences once the sun comes out.
There is a season for everything, but it doesn't mean you have to stop gardening just because temperatures fall. Extending the season is an exciting and rewarding endeavor made easier by knowing a few simple techniques.