t's time to start the salad.
With the end of winter in sight (OK, there's still couple months of cold weather to deal with, but I have to stay optimistic), the itch to get things growing too often exceeds the patience to wait for spring. So does the desire for freshly grown salad greens. Lettuce, spinach and other green leafy vegetables are cool weather plants, and while the seeds like a little warmth for germination, the plants can tolerate cooler temperatures.
Why pay the high prices for commercially grown greens when you can grow your own, even though the ground is covered with snow? The problem is how to get enough light to the plants so they will grow hearty enough to fill our salad plates. The question is whether or not we can get a successful crop this time of year or are we jumping the botanical gun?
Numerous studies and experiments, not to mention volumes of written information, explain the how-tos of extending the growing season. Maine gardener, lecturer and teacher, Eliot Coleman, wrote in his book, ''Four Season Harvest,'' that each layer of protection we give our plants can extend the growing season by one full zone. Even if we can't pile plastic and nylon on top of our gardens to keep them warm in winter, there is a way to grow fresh greens when the ground is covered with snow and temperatures are well below freezing, and it doesn't cost a fortune.
The solution is to build a cold frame or a hot bed. There is a difference between the two, but one structure can serve as both. A hot bed is a heated structure, while a cold frame relies on the sun to keep the plants warm. Some gardeners use commercial gardening heat pads or cables, or in some cases, gutter cables, in the bottom of the structure to germinate seeds and retain heat. If the cold frame is structurally sound and air tight, seeds can be started indoors and seedlings hardened off and later moved to the cold frame. If placed in the right location, where it will get plenty of sunlight during the day and protection from cold, north winds, a cold frame can generate enough heat to keep the internal temperatures above freezing overnight.
Cold frames are generally placed with the back of the frame against the house. Be sure not to place the cold frame where icicles might form overhead or they could fall and break the glass. The frame should be taller in the back than in the front so the glass can be angled to get the most of the sun's rays. If you are handy or know someone who is, have them cut the frame's back at about 12- to 18-inches tall and the front eight to 12 inches tall. The sides should slope to fit the back and front. Discarded windows work well as a top for the frame and can easily be hinged to the box. On warm days or when the sun is shining through the glass, prop open the lid with a block of wood or open the lid completely. Be sure to close the lid around 2 p.m. so the box can retain enough heat to get through the night.
Lettuce isn't the only thing you can grow in your cold frame in winter. Radishes, spinach and many varieties of mache and arugula can enhance your salad plate within a month of planting. Spring onions also can be grown, although they take a bit longer than the greens. You also can use your frame to start other cold weather plants, such as broccoli, cauliflower and cabbage, so you have healthy young seedlings to place when spring finally does arrive.
The growing doesn't stop here. With a bit of imagination, you can create portable cold frames that you can move around your own garden bed to cover already growing greens in late fall and extend their growing season. If the temperatures get extremely cold and the sun hasn't particularly cooperated to provide enough heat, floating row covers can be placed over the vegetables inside the frame for even more protection.
Regardless of where your frame is located, it should be placed over well-drained soil. If drainage is a problem at your chosen site, you can excavate the bed about eight inches deep and replace it with about six inches of gravel or coarse sand. If you are building a hot bed and plan to put heating cable beneath the soil, bury the cable in about two inches of sand and cover it with hardware cloth before adding planting soil to the frame.
I plan to get my frames going within a couple weeks and hope to have fresh salad greens on my plate before the March winds quit blowing. Check out my blog ''Eating to Live'' at www.tribtoday.com for progress on the frames and plants.
Evanoff is a Master Gardener with The Ohio State University Extension of Trumbull County. She can be reached at firstname.lastname@example.org.