Early Spring and late Fall Father Frost often pays us a visit and freezes the water within the leaves of our plants. One of ways you can defeat Frost and extend your growing season is to cover your plants with a blanket.
Frost blankets varies in width and length as well as the thickness or weight of the material. The blankets I use are 6′ x 50′ and provide 4 degrees of protection per layer. In practice I find this to be a conservative estimate. Last fall I planted spinach and not only did the crop flourish but it also survived frosts down to 8 degrees Fahrenheit. In addition to frost protection there are other advantages to covering your crops with a blanket.
The recommended practice is to fit the blanket loosely so the plants have room to grow. The porosity of the blanket allows water to penetrate the fiber so once it’s in place there’s no need to remove it for watering. Finally the blanket provides protection from the wind and reduces drying and therefore the need to water frequently.
Here’s a chart that demonstrates the frost protection of a double layer blanket. My Spinach crop – normally able to sustain temperatures down to 20 degrees Fahrenheit actually survived two frosts with the temperature dropping to 8 degrees.
While I relied upon the weather service for the temperature readings it was clear to me that the blanket was doing it’s job as other crops in the same area (West Plains Community Garden at Don Warden City Park) were frost burnt including spinach, broccoli and lettuce.
Planted in mid October, I began harvesting the week of Thanksgiving and continued until mid March when the bed was abandoned. Though frost blankets restrict light by 15%, growth was vigorous – considering that the crop was grown during the winter months. Though some crops would require a hooped frame to grow to maturity there’s little doubt that winter gardening is possible in the West Plains area. Some other obvious candidates would include carrots, cabbage, lettuce, onions (green and bulb) , and cauliflower.
For the most part, spring is the time when the blankets prove most useful in getting a head start on planting. Not only do the blankets help hold the heat of the day but they also deter evaporation. In clay soils that harden when dry – and even crack – the blankets act as a mulch. Tender seedlings are also protected from wind and heavy rain.
Getting an early start on melons and cantaloupes planted in a mound I decided to use tent pegs to raise the blanket because the seedlings were just beginning to show true leaves and needed additional protection.
Other possibilities for raised blankets are hooped frames using PVC piping, peaked roof wood frames, and woven fabric like hardware cloth or chicken wire. There’s really no right or wrong way to raise the blanket as long as you have a means of securing it. A thin bead of silicone on PVC will do the trick as will staples on wood – though using a piece of cardboard as a washer is recommended to keep the the fabric from tearing away from the frame. Clothespins are often used for wire frames.
Using the tent pegs and securing the blanket with rocks – plenty of those in my garden – was the simplest means of covering my melon and cantaloupe starts. I might have used wood stakes precut or salvaged from used lumber, but the pegs where readily available and because I do a lot of camping I have plenty of them. Just make sure that the edges of the blanket are snug to the ground.
So don’t be afraid to use what you have on hand. Be creative and frugal. I’ve yet to get any complaints from the plants themselves, and in fact they seem to appreciate being tucked in and cozy.