How to Build a Low-cost Greenhouse With Pine Poles

A greenhouse can be a reliable source of fresh winter food, and this low-cost greenhouse made with pine poles is a great DIY option.


| January/February 1985



091-027-01

The transparent roof should be as nearly normal (at right anges) to the sun's rays as possible to maximize light transmission and minimize reflection.


MOTHER EARTH NEWS EDITORS

In our pan of northern California, maintaining a high level of food self-sufficiency isn't just practical — it's all but necessary! We live in the Mendocino National Forest region, and — though this may come as a surprise to people who've never visited the upper portion of the Golden State — from November through May, the road from our ranch to town is often impassable. (Our mountainous, 4,000-degree-day area has quite a variable climate. Although it rarely gets below 16 degrees Fahrenheit, it can also snow in June!) 

Therefore, we've learned to rely on homegrown food during the winter months. Much of our cold-weather stockpile consists of stored produce from our summer garden; but not long ago, in search of more culinary variety and vitamins, we decided to build the low-cost greenhouse pictured in the image gallery. Its performance as a producer of fresh winter foods has surprised even us, and there's no reason why anyone with a suitable south-facing piece of soil can't duplicate our do-it-yourself greenhouse.

A Low-cost Greenhouse With Careful Design and Simple Construction

If money is no object, I suppose a person could spend just about any amount of cash on a contractor-built greenhouse. However, not only were we determined to grow our own winter vegetables, but we aimed to do so without generating start-up costs that would effectively have us paying triple the store-bought price for our homegrown produce for years to come.

First of all, we arranged with the U.S. Forest Service to purchase a number of knob-cone pines growing on a ridge near our home. The price was right (low!), and pole-building construction is both effective and easy to learn. We glazed the structure with sheet plastic and simply worked the soil within the greenhouse to avoid having to build expensive and complicated growing beds. Finally, the greenhouse doesn't cost a thing to operate (other than what we spend to fertilize and water the plants), because it uses only the sun's energy for heat, right on through the clouds and snow of winter.

In order to get that kind of efficiency from an essentially crude structure, we had to do a good bit of planning before we set to work. The angle of the roof was calculated to allow the maximum transmission of light (see Fig. 1 in the image gallery), and we chose a site on a south-facing slope, where the greenhouse would effectively receive more energy per unit of area than it would on level ground (Fig. 2).

Proceeding From Pole to Pole

Before actually beginning construction, we carried the poles (which had been stripped and allowed to cure), as well as all of the rest of our materials, to the site by hand and wheelbarrow, to eliminate the risk of erosion due to soil disturbance on the slope. The poles, of course, tapered from one end to the other. We used the thicker portions (they averaged about 6 inches in diameter) for the load-bearing parts of the structure and the thinner ends to frame up the doors and windows. Fig. 3 details the sizes of poles and nails used in each application.

robert
6/16/2016 5:40:54 AM

Hello, Great article for all of us living in hills. Is it possible to get the missing figures? Thanks.






Crowd at Seven Springs MOTHER EARTH NEWS FAIR

MOTHER EARTH NEWS FAIR

Sept. 15-17, 2017
Seven Springs, PA.

With more than 150 workshops, there is no shortage of informative demonstrations and lectures to educate and entertain you over the weekend.

LEARN MORE