Build Your Own Frosty Frame: Jump into planting season
Extend your planting season with a cool frame! Building your own cool frame is an effortless way to keep your plants growing all winter long.
Below is an excerpt Four-season harvest By Eliot Coleman. It has been adapted for apply on the Internet.
What is a cool frame?
Gardeners should dedicate a monument to the cool frame.
It is the simplest, most pliant and most effective low-tech tool for modifying the climate in the garden. It’s straightforward because it’s basically a box with a glass top and no bottom that sits on the ground.
It is pliant in that it can be as long, wide or as high as the gardener desires. And it worked, because it is a proven gardening aid, used in one form or another since age-old times (mica sheets were older than glass).
The cool frame was the basis for the early development of intensive commercial horticulture.
How a cool frame works
The cool frame reduces climate stress in many ways:
Temperature
A single layer of glass creates a microclimate where the nighttime temperature inside the frame can be as much as 20° higher than the outside temperature, although the average difference is between 7° and 10°F.
The daily temperature inside the luminaire, even on a murky, early spring day, will range from 10° to 15°C.°F warmer than outside. On a radiant spring day, the temperature can rise enough to cook the soil and plants if you don’t dissipate the extra heat.
Temperature differences day and night depend on the seasonthe angle and intensity of the sun, the rate of change of external temperature and the initial temperature in the frame.
Moisture
Much of the devastation that freezing can wreak on winter vegetables is due to the humidity of the plants.
High humidity helps protect plants from the cool, but plants sitting in puddled, rain-soaked soil before freezing will be more stressed than those that are drier. The cool frame glass roof protects the crops inside from massive winter rains.
Wind
Wind can make a chilly day very cool. Weather forecasts always mention the wind chill factor.
The same conditions affect plants. Wind cools by removing heat from the environment and evaporating moisture. The stress of winter wind alone can mean the difference between life and death for hardy vegetables.
Even the slightest wind will support. This was proven by two beds of spinach planted a few September ago for wintering outdoors.
One was lightly covered with pine bough litter, the other was left uncovered. Although the spinach could be clearly seen through the slim layer of pine boughs, this minimal wind protection was significant.
90% of protected spinach survived the winter compared to 10% of unprotected crops.
Building a cool frame
As already mentioned, a cool frame is a bottomless box that sits on the ground and has a glass cover. So there are two parts – the sides (box) and the top (glass).
The sides can be made from almost any material – boards, concrete blocks, hay bales, logs, etc., and all of them have their advantages.
From our experience, we suggest making the sides from boards. This will give you a frame that is sturdy, effortless to build, effortless to apply, relatively airy and portable.
The top covering is called a airy.
In the elderly days, lights were 4 to 6 square feet in size and consisted of overlapping sheets of glass. They were massive and required two people to carry them. Today’s home gardeners often apply elderly storm windows for lighting.
Storm windows are effortless to find and are just the right size to cover cool frames. State-of-the-art lamps can be glazed with translucent materials other than glass, such as plastic, polycarbonate, or fiberglass. Depending on the size, the cool frame is covered with one or more lights.
The cool frame can be any width that the lights will cover, and any length and height.
Customary home garden cool frames measure 4 to 6 feet from front to back and are 8 to 12 feet long.
They are arranged in a long dimension running from east to west. The frame should be high enough to accommodate the plants you plan to grow.
In the standard version, the rear wall is 12 inches high and the front wall is 8 inches high, so there is a slight slope towards the south.
Some experimenters have built frames with lights at a 45° angle facing south to maximize sunlight in midwinter.
Such frames do not work as well as established low-angle models for two reasons.
First, you don’t need maximum heat in the middle of winter to get hardy plants. The only thing they require is frame protection. Secondly, there seems to be some benefit to having a glass roof near the plants as if it were a layer of snow.
The environment inside established low-angle frames better suits the needs of resistant crops.