Seasoned Farmers

Summer 1999
Eric Sideman and Eliot Coleman
Eliot Coleman talks with Eric Sideman of MOFGA and others about the effects of cold temperatures on plants. English photo.
Barbara Damrosch
Barbara Damrosch, along with Eliot Coleman, are the only employees of Four Seasons Farm in Harborside. They supply fresh produce year-round to retailers within a 25-mile radius. English photo.

By Jean English

Judging from the crowd of well over 200 growers – many of them youthful – who attended MOFGA’s Spring Growth conference, year-round production could take off in Maine soon. The conference, “Year-Round Production and Marketing,” featured three farms where year-round production is or has been a reality, two where the practice is just taking root, and a talk on the physiology of plants that are stressed by cold.

Eliot Coleman and Barbara Damrosch of Four Seasons Farm in Harborside, Maine, talked about growing and marketing salad mix and other freshly harvested vegetables from October through May. Coleman said that years ago he ran a market garden for four months of the year, then the market was “handed back to Californians for eight months. Who wanted to do that? I wanted to keep the market here.” But would year-round production find a year-round market in an area that is considered summer territory by so many? “We wondered how it would work without the summer people,” said Damrosch. “We were staggered by the response. People knew the difference” between their fresh, local produce and the aged stuff that’s trucked in from afar. In fact, in the spring of 1998, when rains flooded California and interrupted the supply of produce from there, “stores called us,” said Coleman, “and wanted to double their orders. I thought, ‘Yea Maine! Go for it!’”

Coleman showed a slide of a high tech greenhouse in Europe and said that even though the greenhouse was producing year round, “that’s not what I wanted.” The next slide showed a farm south of Paris where produce was growing throughout the winter in simple, homemade structures. Coleman also saw a farm that was using Dutch lights (cold frames with glass covers made especially for them).

Coleman came back to the States and started experimenting with growing vegetables in cold frames covered with Dutch lights at the Coolidge Center in Masssachusetts. Then he moved to Vermont, where he experimented with mobile greenhouses. Eventually he combined the two technologies by putting up a 17′ x 32′ greenhouse covered with standard greenhouse plastic and setting cold frames covered with Dutch lights in it. The cost “was well under $2 per square foot to build. When you go into the greenhouse,” said Damrosch, “you’re in New Jersey. In the coldframes, [the climate] is Georgia.”

Coleman then had the idea of, rather than trying to fight nature and grow heat-loving vegetables all winter, trying to find hardy crops that preferred to grow in cool weather. In the summer, his greenhouse would cover tomatoes and other crops that are difficult to ripen in northern New England; then he would slide it over the coldframes, where hardy crops had been started and would continue to grow into the fall. With this early setup, he found that sliding his greenhouse from its wooden base around the tomato plot onto the winter plot was made easier by lubricating the wood with liquid soap. Also, by moving the greenhouse, the plot that it had covered in the summer was exposed to the action of snow, rain and frost, which helped control pests and reduced the buildup of nutrients.

In the fall of 1995, Coleman and Damrosch, now in Maine, “decided to go commercial” and put up a 30′ x 100′ greenhouse, which, despite its size, is still movable: it rolls over ball bearings set on posts. For the commercial scale, they wanted “a more practical cover than the cold frames inside the house” and found that spun polyester fabrics worked well. “There was no wind [inside the greenhouse], so we didn’t have to tie them down. They’re supported on square-topped wire wickets. Research said that the flatter the surface [of the fabric], the warmer [the air would be] under the surface.” They tried both single and double layers of plastic on the greenhouse, with the double layer inflated, and found that the difference in crop quality was insufficient to warrant the double layer.

Crops do freeze under these conditions, where the temperature can drop as low as 15 degrees on a cold night, but they’re fine when they thaw. Coleman believes that protection from wind helps prevent winter damage to the crops.

At this point, Coleman and Damrosch have 12,500 square feet under cover: three 30′ x 100′ houses; two 30′ x 50′; and one small house. (They also grow crops outdoors in the summer, for a total of a little under two acres under cultivation.) One house is heated to just a little over 32 degrees for crops that are slightly tender. Coleman and Damrosch are experimenting with water pipes that send heated water down paths in a greenhouse to warm beds that are covered with fabric. Despite their larger size, these houses are still moveable – with a tractor and cable. Coleman is pleased with the Harnois greenhouses made by a Canadian company and sold by Greenhouse Supply Inc. (P.O. Box 97, Orono ME 04473; 1-800-696-8511).

Among the crops grown are spinach, claytonia (Claytonia perfoliata or Montia perfoliata, a native American wild plant, also called miner’s lettuce, which grows wild in California and is not the same as the Claytonia that grows in Maine’s woods); mache (a traditional European winter green – ”the only one where we harvest the whole plant and then sow it again”); and narrow stemmed chard, which “does much better than regular Swiss chard” and is cut leaf by leaf; the thick leaves have a mild taste. This plant also goes by the British name of ‘perpetual spinach,’ which Coleman thinks is “designed to give children nightmares.”

Another crop is tatsoi, which is tender and mild. “We try to keep our mix mild; customers are not used to the strong taste of some mesclun.”

Beet leaves (‘Bull’s Blood’) give salads a “wonderful red color” and don’t have the bitterness that radicchio can have. ‘Red Ace’ beet leaves have red ribs that also color the mix.

Minutina is firm but not fibrous; arugula is hardy.

One crop that Coleman was particularly excited about was watercress. “An unheated greenhouse is cold, dank and moist – conditions watercress likes. After cutting it, there are new roots on the stem that aren’t in the ground. We throw a layer of compost over it to bury the roots and get a second, even a third crop.”

Coleman pointed out that richly colored salad mixes have four to 10 times as much vitamin A as the iceberg lettuce that’s on supermarket shelves, and they have more specific health compounds, as well.

A homemade salad mixer made of wooden slats holds 80 pounds of mix – “more than we want on a given harvest day,” said Coleman. They wash each leaf shape separately, because “it’s easier to see things that shouldn’t be there” that way – then they put the leaves in the mixer and turn it very slowly. This washing, mixing and packing takes place in a heated end of the greenhouse.

In addition to their salad mix, Coleman and Damrosch grow a stir fry packet with such crops as leeks, turnips and carrots. These are put in cellophane bags obtained from Altapac (800-888-7019).

Four Seasons’ carrots, Damrosch and Coleman have been told, are the “trading item of choice in grade school lunch boxes.” Many parents tell them, “That’s the only vegetable [their child] will eat.” Their winter carrots are marketed from November 1 through the end of February, then they’re sold out. The sell them with 1-1/2″ of green top on them, to distinguish them from the carrots that they start on January 1 in the greenhouse and sell as bunches of baby new spring carrots. The latter are not as sweet as those from the winter, which is why they sell them differently.

Early potatoes are another specialty crop of Four Seasons. “We start sprouting them in mid-February and have them in the ground [in greenhouses] by mid-March.” They are selling baby potatoes by mid-May.

Broccoli is also ready by mid-May. ‘Emperor’ is the variety that has worked best for them.

Heat-loving crops grow in the greenhouse in the summer. These include eggplant (‘Orient Express’ is a favorite), tomatoes, melons (‘Gold Star’ muskmelon and French Charentais are favorites, although customers took a while to get used to the small green Charentais); peppers; zucchini (sold when 3 to 4 inches long); cucumbers and sweet potatoes. Coleman mentioned that he keeps tomato seedlings from growing too tall by “brushing” them – i.e., he ties a piece of used Reemay onto a stick and brushes it along the tops of his plants. “It makes them think it’s windy and they get stockier,” he said. One summer, sweet clover was grown in a house that would otherwise have been empty. The crop is heat resistant and grew very well – but needed to be irrigated.

When plots outside of the greenhouse aren’t being used, rye and vetch are grown on them.

The plots at Four Seasons are immaculate: not a weed is seen, and crop plants are perfectly spaced within rows that are perfectly straight – because they are sown with a Pinpoint seeder (available from Johnny’s). Coleman praised this seeder highly and said that he also uses it to start seedlings in beds in his heated greenhouse.

One problem with year-round harvesting is that “it’s a lot of work.” Coleman and Damrosch say that “next year we may take the summer off.” How so? They deliver produce three times a week in the summer and twice a week in winter. If they grew storage crops outdoors in the summer and delivered them in the winter, along with their hardy greenhouse crops, they would simplify their operation.

They do not want to increase their farm size. “As important as ‘organic’ is the word ‘fresh,’” said Coleman. “We have all the business we can handle within a 25-mile radius of our farm. ‘From farm to shelves in under 12’ ” is a motto they like. Such freshness “is something a far away grower can never deliver. We want to see small farms all over the place.”

When asked about irrigation, Coleman said that he uses a stake sprinkler attached to a hose to water some plants during the warmer months. “Griffin Greenhouse Supply sells overhead irrigation systems, but they’re more expensive than stakes. They work beautifully. From November to March, basically there’s no watering. The sun is low and the water table is high.”

Regarding ventilation, he said that 50-foot houses can simply be end-vented. He rejected roll-up sides because he would have to shovel snow to get at the sides to roll them up sometimes, and he didn’t want cold air coming across the crops. Coleman did suggest that starting roll-up sides 4 feet up the greenhouse might make more sense than starting them at ground level.

Insects have been minor problems, even in Four Seasons’ immovable greenhouse. Aphids once got into a crop of spinach that overwintered in the ground. “Voles are the one pest we have,” said Coleman. He uses traps along the walls to catch them.

Asked about the minimum size greenhouse that one should get initially, he said that a home gardener should have a 12′ x 20′ or larger. Commercially, larger is better (to a point). “Once you start putting out a quality product, the demand is there.”

Coleman and Damrosch set their prices before they go to market. They figure “what we need to get to make it worthwhile doing this.” Their wholesale prices are $6.25/lb. for salad mix; $3.00/lb. for bulk spinach; $1.25 to $2.00 for carrots; and $3.00/lb. for baby turnips. They dropped scallions as a crop. “I don’t know how California is doing it” as far as producing, transporting and marketing scallions for a lower price than a local grower can charge, said Coleman. They are trying to replace their scallion market with Walla Walla sweet onions for an early spring crop.

The techniques used at Four Seasons are discussed in Coleman’s books The New Organic Grower and The New Organic Grower’s Four Season Harvest. His most recent book, The Winter-Harvest Manual – Farming the Back Side of the Calendar, is worth the $15 price tag (includes postage) for the planting dates and lists of varieties, tools and supplies alone – and it’s got much more. It updates the Four Season Harvest regarding technical and biological details, crops to grow, harvest times and techniques, pests, greenhouse design and more. The self-published, 57-page book, copyright 1998, is available from Coleman at Four Seasons Farm, RR Box 14, Harborside, ME 04642.

David Cohlmeyer
David Cohlmeyer of Cookestown Greens in Ontario stressed the need for careful accounting in farming. English photo.

Chef Turned Grower

David Cohlmeyer of Cookestown Greens in Cookestown, Ontario, spoke next. Cohlmeyer is a chef-turned-farmer who has emphasized building a production system that will hold his customer base all year by producing salad and storage crops for the off- season. He has emphasized the need for good record keeping to ensure profitable production.

Cohlmeyer grows 14 acres of vegetables and markets mostly to restaurants. (He also sells at a farmer’s market in Toronto on Saturdays.) He once had his own restaurant, but it took too much of his time; so he started catering and writing about food. He learned about organic foods and alternative agriculture while doing his food column.

Next he turned to restaurant consulting for hotels and restaurants. He found that other chefs were looking for quality food. “When I was a chef, if I got a quality product, customers would say, ‘How did you prepare this carrot?’ I couldn’t often find that quality.”

Cohlmeyer decided that it might be easier for him to learn how to farm than to try to change other farmers. “I found that farming is a lot more work than I thought it would be – but it’s rewarding. The key thing to farming, he said, “is having a steady supply of produce and being consistent regarding quantity, size, quality and delivery time.”

He has an underground root cellar and continues to learn about quality by working with harvest times, storage temperatures and other conditions. “It’s not always the same as the Department of Agriculture recommends,” he warned. He has learned, for example, to harvest root crops with soil remaining on them, then to wash them when it’s time to sell them. He recommended that growers buy a walk-in cooler before they buy a tractor.

However, “Don’t get everything too cold,” he warned. “Don’t put tomatoes, cucumbers, basil or peppers in the refrigerator.” The latter might keep best in a room that is simply cooled with an air conditioner.

While Cohlmeyer uses row covers early in the spring to get an early start, he finds that they are more effective in the fall for keeping the season going. “Growing for the late market offers more possibilities than for the early market.” He modifies the summer climate by growing such crops as mustards and lettuce outdoors under shade cloth.

To grow for the late market, Cohlmeyer reminded farmers to “remember to get fall crops in by late July or early August” and to “keep experimenting with varieties.” With spinach, for example, “a lot of the new [varieties] are fast growing, but you might be better off with a slower one. ‘Bloomsdale’ is slower but doesn’t bolt in summer as readily and is more frost hardy” than some other varieties.”

While Cohlmeyer uses rotations to keep crops healthy, he said that he thinks “there’s more to rotations. When do employees want to work? What types of crops do customers want? Customers are part of the rotation. There’s temporal rotation – growing different crops at different times. But you can do it spacially too – with one crop growing right next to another. Weeds are doing that.”

He has found that chefs are a key to his marketing strategy. “I tell my customers why we’re so good at what we’re doing. I give them a little story … The chefs tell the waiters who tell the customers – and the waiters get bigger tips. It’s goodwill. Be friendly. Chefs say they like buying [from us] because we’re not always complaining about the weather or the late spring … Be positive about what you’re doing.”

Cohlmeyer has noticed less interest lately in new and interesting vegetables. “Chefs like to know they’re there, but they don’t really want to buy them. So try new things on a small scale. Every now and then you’ll get one that’s a winner.

“Be aware of the peculiarities of the market regarding timing,” Cohlmeyer advised. “I think summer leeks are the best, but people are not ready to buy them in the summer. So I put summer leeks in the root cellar and sell them around October 15, when people want them. [He hills leeks, by the way, to get long, white stalks.] People want Jerusalem artichokes in the summer, so I harvest them in November and leave them in the root cellar in the winter and sell them in the summer.” He grows French and German varieties that don’t have knobs.

Cookestown Greens sells to 35 customers, and Cohlmeyer “would rather have fewer than more.” Still, he had this advice about publicizing your farm: “Send a story about your farm to newspapers. It’s free advertising. Send a newsletter periodically to chefs and a copy to the media.” When he’s done this, he’s found that “within two or three weeks, I’ll have two stories in the media from some aspect of the newsletter. Write [the stories] yourself or pay someone to write for you.”

He also advised that growers “keep the word out about organics and the political aspects of food, about where food is coming from. Say, ‘This isn’t quite right.’ Don’t say too much about it. You’ve got to get the message to the owner [of the restaurant.]. Tell chefs to pass your newsletter on to the owner, or just leave it on their desk. Distribute pesticide ads – They say it themselves; they’re the best advertisement for organic agriculture.” He recommend The Ram’s Horn, a monthly newsletter of food system analysis, as a good resource (The Ram’s Horn, 125 Highfield Rd., Toronto, Ontario M4L 2T9; Tel. 416-469-8414). He also advocated leaving copies of articles from mainstream media out for chefs and owners to read – such as the Michael Pollan’s New York Times article about genetic engineering (“Playing God in the Garden,” The New York Times Sunday Magazine, October 25, 1998).

Another way that he educates is to have hotel personnel come to work on the farm for a day and serve a meal for the farm help. The customer gets to see how the crops are produced, and the farm help finds out how the crops are used.

Cohlmeyer operates on a larger scale than Coleman and Damrosch (who are the sole employees at Four Seasons), and thus needs more employees. Last year he cultivated 14 acres and had about 10 employees, which, he said, was a good number for him. This year he will cultivate about 15 acres, which will be the maximum scale for him, and will have to increase to 12 or 13 employees. “One person can supervise no more than 12 people – so I become a manager and don’t get my fingers dirty. But if I have a few hours, I go out and ask what I can do.”

While slides of Four Seasons’ vegetable plots showed Coleman’s near compulsion to eradicate weeds, slides of Cookestown Greens showed just the opposite. “I’m working with the fertility of the soil,” said Cohlmeyer. “Next year I’m going to grow a crop in half of the fields, and leave the other half fallow.” He’ll let one or two flushes of weeds grow, cutting them before they drop their seeds, because “I think weeds know what’s needed to fix the soil … I’ll do any compost [applications] and deep digging in June, then let [the weeds] grow, then cut them, then plant cover crops – maybe one or two crops of buckwheat, then rye for areas to be seeded late next spring and oats where I want to get in early in the spring. I can seed right into oats if I need to.” Cohlmeyer said that in general he follows a rule about timing of seeding: “If you need boots, you don’t go out into the fields.”

The following year, the weed pressure will be low enough that weeds won’t interfere with crop plants. “I’ll let them grow right in with the crop and drop their seeds. Then [the weeds will] grow the following year [on the fallow plot]. I’m getting away from cultivating for weed [control] and am only cultivating to break the surface” of the soil, to prevent crusting and to allow water to penetrate.

Cohlmeyer also uses a “hodge podge” method of green manuring: He calls seed dealers to find out what old, odd lots of seeds they have. He plants those seeds, and when the plants begin to flower, he mows them, tills them in, then plants another crop. This method is said to add 40 tons per acre of organic matter.

Cohlmeyer buys manure – mostly sheep and a little cattle – and composts it for at least a year before using it. He windrows it and turns it with a bucket and manure spreader. The windrow is covered with a synthetic felt material to keep the moisture in and the weeds down.

Witch grass is the main weed problem at Cookes­town Greens. “Leave it out in the sun for two to three days” after tilling it up to control it, Cohl­meyer said.

A chisel plow is used occasionally to crack hardpan. Rototillers are not used because Cohlmeyer believes they are “too violent on the soil.” Instead, he uses a Rotera power harrow, which “stirs the soil instead of turning it upside down.” The resulting seedbed is not as fine as one obtained with a rototiller, but is good enough. (Lely stopped making Roteras in 1938; Cohlmeyer bought his used.)

Cohlmeyer told a poignant story about his flame weeder. “The guy who made it had a friend who died as a result of a chemical spill. Now he says he’ll do anything for an organic farmer.”

A ‘Real’ wheel hoe from Johnny’s is “good for close cultivation,” and although Cohlmeyer balked at the price (about $300 in U.S. dollars) initially, he has since found the tool indispensable.

Cohlmeyer grows ground tomatoes outdoors and finds that they’re “not affected by weeds at all.” In fact, he simply bush hogs over the weeds that grow above these plants, and “the weeds put nutrients right back into the soil.” He finds that the tomatoes “need a bit more water,” but warns that “some crops don’t like weeds, so you do have to weed them.”

In his greenhouses, Cohlmeyer’s main crop is a baby salad mix – and the farm is known for the abundance of beautiful, edible blossoms that it produces. Customers also like the red color of ‘Bull’s Blood’ beet leaves and the taste of fava beans, both of which do well in his greenhouse. Edible flowers are sold as a mix, too. “We don’t get much money for them but we got known for them.” Marigolds are a favorite, and dahlias “have very interesting flavored roots. Rather than compete with a simple California salad mix, we have our own unique mix.”

Cohlmeyer warms his greenhouse soil by running hot water through pipes that are 2 feet underground and spaced 6 feet apart. A tensiometer measures soil moisture, and drip irrigation is used to speed germination.

Unsatisfied with Reemay, which tears easily, Cohlmeyer now uses a polyethylene from Easy Gardener in Texas that has 200 holes per square inch – enough to keep flea beetles out. He uses it two or three times before it tears, then it “makes a good shade cloth.”

In order to keep his plants short and stocky rather than elongated – without using growth hormones – he provides a warm night and a cool day in the greenhouse. Grow lights go on around 2 a.m. and are off at 3 p.m. He believes that the ability of northern growers to regulate greenhouse temperatures in this way – combined with an eventual banning of growth hormones – is “why the bedding industry is going to move from the South to the North.”

Circulating horizontal air flow fans jiggle leaves to keep plants shorter and healthier. High intensity sodium lamps, used at 1/4 the rate recommended, eliminate aphid problems, provide light and heat, and produce healthier plants. “All of the electricity” for the lights “gets turned into heat.” (Note: Electricity is cheaper in Canada than in the United States.)

In addition to the above greenhouse, Cohlmeyer has a cold greenhouse in which he suspends 2-liter soda bottles full of water to add heat. “Fifty-gallon drums don’t melt and heat fast enough,” he said. “You need more surface area. When water freezes, it gives off a tremendous amount of heat.” Also, a space heater in his greenhouse comes on when the temperature drops to 24 degrees F.

Other specialty crops grown at Cookestown Greens include beet berries (the fruit of a Chenopodium, available from J.L. Hudson, Seedman, PO Box 1058, Redwood City CA 94064); winter squash (‘Gold Nugget’ is a good keeper, and chefs like to put it in soup); finger potatoes; and dried tomatoes. Apple wood is used to smoke some tomatoes – making “vegetarian bacon,” says Cohlmeyer. He uses half solar and half electric heat to dry tomatoes for about 40 hours.

He is experimenting with ‘Green Zebra,’ a keeper tomato, which he harvests in September and markets when it ripens in December through February. “Some years it’s great, some years it’s not.”

Ground cherries “are great for keeping. Keep them warm and dry. They may dry up, but then they have – like a raisin – a more intensified flavor.”

He triggers the sprouting of ‘English Sprouting’ broccoli by “going in in October and chopping the roots with a shovel.”

He digs radicchio in the fall, transplants the roots to the greenhouse, and gets succulent, small, red leaves from the plants from December through February. Plants that aren’t brought in from outdoors produce “the first vegetable up in the spring. The deer love it.”

Cohlmeyer started growing winter radishes a couple of years ago and finds that they store well in the root cellar. He grows black and white salsify, also; the black stores better but the white is easier to harvest.

He grows burdock and is “still trying to get a market for it. A couple of top chefs in the area are starting to use it. It tastes really good in winter.” He grows it the Japanese way – in soil-filled baskets that are set on the ground, making it easy to harvest in the fall. “Pull the basket up and the soil falls away.”

‘Golden’ beets are one of his favorite crops, but he’s had trouble finding the seed this year. He is also “building a nice market for different colored carrots.”

Chinese artichoke is actually “a mint grown for its root. It was common along the East Coast in the last century. It’s difficult to harvest,” but cleaning the roots in the winter “is a good job.” The nautilus-shaped, pearly-white roots “don’t have much flavor but have a crunchy texture.”

Regarding the financial aspect of this business, Cohlmeyer says that a grower “should start farming for profitability rather than productivity. It’s possible to make a living on a small organic farm.”

He outlined six steps toward profitability: 1. Calculate your costs of production. Every university and community college has teachers who can help you figure these costs. He referred to his article, “Keep tabs on costs of production” from Growing for Market (Oct. 1994) as a good reference, too. 2. Set your prices. “Don’t just take the price the distributor says he can give you. As an industry, we have to set prices and say this is what it is.” 3. Watch your cash flow. Farming has notoriously slow cash flow. 4. Know your scale of operation. You can have an operation “like Eliot and Barbara, and scale everything for two employees,” or like his, with more employees. “But when you hire people, it takes three people to do the same thing that you do – because you have to pay yourself for managing those people. You need more washrooms, bigger tables, more greenhouses to keep them busy … The numbers show you that hiring someone is a very expensive proposition.” 5. Try to get crops that grow fast. Turnips, for example, grow well and fast in the winter greenhouse. 6. Banks are the cheapest source of money. Work with them. Find a manager with whom you feel comfortable.

He concluded that there are two ways to think about profitability: First, you can lower your costs; or second, you can make all of your decisions based on profit rather than cost. The latter is the “better way to do it.”

Pete Johnson and Paul Gallione
Pete Johnson (sitting) and Paul Gallione gave beginners’ perspectives on off-season growing. English photo.

Just Starting

After hearing about these two successful farms, conference participants learned about getting started from two growers: Paul Gallione, who raises crops in Waldo, Maine, and markets them primarily in Belfast; and Pete Johnson of Greensboro, Vermont. Both started small and are “growing their way into winter production,” said Russ Libby, MOFGA’s executive director.

Gallione said of winter production: “It does work” but “there’s a lot of fine tuning.” He put up his first greenhouse in 1996 and has been producing crops for the last two years – “primarily because I had the planting dates right, thanks to Eliot and Barbara.” Most of his marketing takes place in the spring and fall. “It’s more season extension than winter production.” He put another house up in 1998 and now has three houses (probably four by this summer). “There are a lot of things you have to worry about,” said Gallione: mice, voles, putting plastic up on windy days, snow (“You have to get the heavy stuff off.”), and the need for good drainage around the greenhouse (rather than through it). However, “People want the stuff. I could sell 20 times as much,” he said.

Johnson, whose farm is called Pete’s Greens, grew up on the vegetable farm, then went to Middlebury College in Vermont. For his senior thesis, he built a greenhouse in Middlebury’s zone 5 location, and “it went really well.” Now he grows mesclun and a braising mix (kale, collards, beet greens, ‘Bright Lights’ chard and a dozen other crops that taste best when they are cooked just slightly) in 10,000 square feet of greenhouse space back home – in zone 3 – and is “very successful. This is the easiest stuff in the world to sell.”

Johnson said that “you can sell in places where you wouldn’t even imagine. Places that have a couple of rotten cabbages all year.” When people start to find that they can get fresh salad and braising mixes locally and reliably, “the word spreads.”

He cuts his crop into 5-gallon pails using a sharp knife, which is less tiring on the hands than scissors. He plans on trying mesh bags instead of pails this year. After cutting his crop, Johnson takes the wheels off of his lawnmower and runs over the bed, chopping remaining plant material down. Then he places a layer of compost mixed with river silt over the bed and plants again.”

Johnson just put up a 30-cent-per-square-foot greenhouse using cedar posts up to 5 feet high and spruce and fir logs. The structure is braced with cable, which was tightened with a come-along. “It looks like a barn,” he said. The gable roof sheds snow. By having a warm house, a cooler house and a coolest house, he has different niches in which to grow different crops.

“You could definitely do [off-season production] through the whole winter if you wanted,” said Johnson, but he limits himself to the March 15 through Christmas dates so that he can take a couple of months off.

A Chilling Talk

Next, Cecil Stushnoff of Colorado State University, who has been studying factors that influence the cold-hardiness of plants, spoke. He discussed the effects of soil type and moisture content on the speed at which soils warm and the length of time they hold that heat. Sand heats faster than loam, which heats faster than clay, which heats faster than organic peat, he said. He also mentioned that at cooler temperatures (below 40 degrees F), as are found in off-season production, carbohydrates are not metabolized as much as at higher temperatures; instead they are stored, which probably accounts for the sweeter, better crops produced under cool temperatures.

Stushnoff said that the combination of cool temperatures and high light intensity can cause much worse chilling injury than cool temperatures combined with low light intensity.

Most of Stushnoff’s talk speculated on the relationships between research on chilling injury and the practice of growing crops off season. He also mentioned some practices that might interest growers. For example, he has seen strawberries grown under clear plastic mulch, which “has a huge effect in enhancing yield,” in part, at least, because the plastic limits desiccation. He said that some people in Argentina soak tomato transplant roots in sugar water before setting them out, since this is thought to minimize chilling injury. He talked about encapsulating grape buds in alginate and sucrose to get better movement of water out of the buds and, thus, get a delay of about a week in budbreak, which helps avoid frost damage. In Georgia, said Stushnoff, growers put vegetable oils on peach buds to delay bud break. Finally, he mentioned the practice of growing red raspberries in 5-gallon pots. The plants are subjected to chilling to satisfy their dormancy requirements, then are put in the greenhouse, where they are induced to flower and fruit.

Anna Edey of Solviva
Anna Edey of Vineyard Haven, Mass., spoke about her Solviva greenhouse. English photo.

Sun/Rabbit/Chicken Heated Houses

The last speaker of the day was Anna Edey, who spoke about her Solviva greenhouse at Vineyard Haven, Massachusetts (see the March-May issue of The MOF&G for a review of Edey’s book, Solviva). Edey said that ‘solviva’ is the name of a Swedish flower (Edey herself is Swedish) that means ‘hope’ or ‘it will at last be the way we wish.’ The word also means ‘sun life’.

After reading a passage from her book, Edey talked about her experience of living in a rustic home that didn’t have a bathroom and about the effects of spreading urine around her yard and watching the plants grow “so much larger” the following summer.

After her house burned down, Edey studied building design for a year and a half, then built a new house that combined solar heat and light – enough light and heat that she could grow vegetables indoors all year. She showed a slide of tomato plants that were four years old – and “very sweet.”

Then Edey’s mother-in-law sent her a newspaper clipping that told about a grower in Oregon who was heating his greenhouse with the body heat of rabbits. “It was like a major explosion in my head,” said Edey. “I stayed up for 24 hours designing a greenhouse. Nine months later, we broke ground.” A community of people from College of the Atlantic, New Alchemy Institute, the University of Massachusetts, and other places came to help build the greenhouse. In addition to housing angora rabbits, her greenhouse was home to 50 laying hens. In 1983, this greenhouse cost $5/square foot to build, not including the quadruple layer of glazing, which was donated by 3M company. (Edey says that she would not recommend quadruple layers now except for the most extreme climates; she believes that a double layer is sufficient. “Just add more animals and more insulation instead of more glazing,” she said.)

Tomatoes were the first crop Edey tried in the greenhouse, but she had problems with ammonia that volatilized from the chicken manure. She took more care to add extra leaves each week and to aerate the bedding in the chickens’ area by plunging a pitchfork into it and rocking the fork back and forth. She cleaned the chicken bedding out once a year. She also filtered the air from the chickens’ area through a box of leaves. While these practices did control the ammonia, she still had other problems growing tomatoes.

In the meantime, she had found that many kinds of greens grew very well in her greenhouse – and that chefs loved them. She was able to get $16/lb. for her salad mix then (the price has since declined as supply has increased), and so switched crops and increased the growing space in her greenhouse by suspending grow tubes from the ceiling. The tubes are filled with a mixture of compost, perlite and vermiculite, and crops grown in them receive a supplementary fertilization of liquid seaweed. Edey has more than 3,000 square feet of growing space in her 3,000 square-foot greenhouse. In the summer, she grew greens outdoors.

Edey invested $150 for a galvanized tank, 7′ in diameter and 2′ deep, below which a fire could be built. Even on the coldest night in winter, the lowest temperature of the water was 50 degrees.

Edey said that insect management in the greenhouse depended on keeping flowering plants. “Nasturtium is the ultimate insect management plant,” she said. “It attracts pests and their controlling insects.” She said that the only reliable way she knows of to control rodents is to build a concrete foundation and floor under the greenhouse.

Regarding cover crops, she recommended buckwheat. “You can cut it down easily with hand tools, and you can plant a crop a few days later.”

Edey showed several slides depicting retrofits – existing buildings (such as the Pan Am building in New York, a school, an apartment building, and more) on which she had drawn greenhouses that could help heat and feed the people who used those buildings.

Solviva was closed this winter for the first time since 1983, as Edey was busy with her book and her Solviva Solar-Dynamic, Bio-Benign Design business and wasn’t able to oversee the day-to-day operation of the greenhouse herself. (Edey sells plans for a 3,000-square-foot greenhouse; four Solargreen homes; a Solargreen Mini-Cabin; a Solviva Garage/Apartment; a Solviva Backyard Food Factory; a Walk-in Coldframe; and Solviva Compostoilets and a Flushtoilet with Composting System.) She said that she hopes to find a committed person to run the greenhouse in the future.

Scroll to Top
Sign up to receive our weekly newsletter of happenings at MOFGA.