The following is an excerpt from the Year-Round Intensive Farming chapter in The Winter Harvest Handbook: Year-Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses by Eliot Coleman. It has been adapted for the web.
Work the lazy garden. You pay rent for it all winter, do you not? Make it earn dividends every month of the year.
—Henry Dreer, Dreer’s Vegetables Under Glass (1896)
If farmed intensively, a small area of land can be very productive. The key to increased productivity is to make better year-round use of every square foot. The most impressive skill of the old Parisian growers was their ability to develop techniques for maximizing output from their one- to two-acre holdings. When looking to expand production on our own farm, given our limited land base, we refer to finding the “hidden farm.” Whenever a section of our land is empty of crops and something could have been growing there, that is the hidden farm.
In our quest to find the hidden farm, the intensity of our cropping has reached the point where we grow almost no green manures anymore because we are growing commercial crops so early and so late. Yes, we lose the organic matter contribution from a green manure, but we gain the organic matter contribution from the root residues, outer leaves, and stems of the harvested crop in addition to the financial return from selling it. We double-crop and triple-crop most of our outdoor fields. We also sow at much closer in-row and between-row spacing than used by large-scale field growers. Not only do we sow twelve rows of baby leaf salads or radishes or carrots on a 30-inch (75 cm) bed in the greenhouses, we use that same close spacing in the field.
Let’s take an area on which we plan to grow carrots as an example. We begin outdoor sowings as early in April as we can. Since we try to have every crop available all the time from the moment we first sell it, there are always fields set aside for later sowings of carrots. Some are areas we won’t need to sow until June or July. Rather than having those fields in a green manure or cover crop until needed, we use them for early production of unrelated crops, such as lettuce or spinach or Asian greens that can be harvested before the upcoming carrot-sowing date. The same holds true for fields where, say, lettuce will be planted later which are similarly used for an earlier unrelated crop.
Through focusing our planning on double- and triple-cropping, we have achieved gross yields per acre that are almost double what might be expected off our small acreage. Because we sell only in local markets (stores, restaurants, our own farm stand), we need to maintain a consistent production level of everything we grow, which requires even more planning and analysis. If we had a market where we could occasionally come in with large quantities of this or that crop and be able to sell it, we could keep every square foot planted continuously with much less forethought.
We keep harvesting hardy crops from our fields as late in the fall as possible in order to reserve the greenhouse space for even later crops. But we were always wondering if we couldn’t do more. In the spirit of Henry Dreer’s quotation at the head of this chapter, why should all those fields not covered by cold houses lie unused during the winter months? Given our climate, the only answer to that seemingly ridiculous question would be to build more greenhouses or sow lots of winter green manures. But the expense of a greenhouse is excessive if all we want to do is winter-over hardy crops for early spring harvest. And there are no winter green manures that can be sown and get established in this climate after our late-fall vegetable harvests.
From these musings, we evolved the idea of redesigning low tunnels for winter use. Obviously, crops that are actually harvested during the winter, like leeks, require the easy access of a walk-in tunnel, but we figured that low-growing overwintered crops for extra-early spring harvest would become an economically viable option if protected by a low temporary structure. For inexpensive overwinter protection of fall-planted crops such as onions, spinach, and lettuce, we now use low structures that we call “quick hoops,” and we have found them perfect for taking advantage of still more of our “hidden farm.”