Letter from Pheasant Hill Farm

Farming under cover -- BIG TIME!
Haygrove Tunnels boost yields and fight disease, by the acre -- or the hectare.

By George DeVault

Editor's NOTE

George DeVault was editor of New Farm® magazine from 1981 through 1991 -- and a long-time champion of local food systems and innovative direct marketing approaches to high-value farming.

He, his wife Mel and 23-year-old son Don farm near the village of Vera Cruz, PA, a little over an hour north of Philadelphia. They've been farming there organically since 1985. They extend their growing season with 6000 square feet of greenhouses, and sell cut flowers, herbs, fruits and vegetables through farmers' markets and directly to customers on their farm through a subscription service.

George continues to edit the Russian language version of New Farm® magazine, and in their spare time, he and Mel have edited and published six books on farming and market gardening.

Almost immediately after I was hired to create the New Farm® web site, I called George for ideas and help ... and he responded.

He showered me with articles he'd written for the Russian New Farm® which had never been printed in the U.S.: a two-part series on Joe Salatin's poultry operation, and a great profile of Steve Moore's innovative greenhouse operation. And he snagged us a translation of a fascinating story about one woman's successful effort to homestead in Russia.

He also passed on many helpful observations, including an email note: "Looking quickly at NF web site, struck me that maybe it's a little heavy
on traditional crops, livestock and marketing." "You're right," I answered, "we haven't gotten up to speed on high-value crops, diversification and
direct marketing. Want to help us get started with a monthly column?" And so was born this Letter from Pheasant Hill.

For more on Pheasant Hill Farm, click here.


For More Information

For more information on Haygrove Tunnels, visit their website at
or contact:

Ralph Cramer
116 Trail Road N.
Elizabethtown, PA 17022

August 31, 2004: When torrential rains threatened to turn western Iowa into this nation’s sixth Great Lake one June about 30 years ago, a reporter from The New York Times phoned then Iowa Secretary of Agriculture Robert Lounsberry for the straight scoop.

It being an election year and all, Lounsberry spared no soggy detail in painting a convincing word picture of the impending disaster. But when Lounsberry had finished, the reporter floored him with a totally unexpected question: “Mister Secretary, I don’t understand. When it started raining so hard, why didn’t the farmers cover their fields?” *

Don’t laugh. That really happened. The big city reporter just couldn’t grasp the difference between, say, the infield at Yankee Stadium and acres and acres of acres and acres in the middle of the Corn Belt.

Today, though, such a comment might not seem quite so silly or naive, especially to innovative producers of high-value crops such as cut flowers, raspberries, strawberries and fresh-market and heirloom tomatoes.

Since just 1996, a new type of greenhouse, “Haygrove Tunnels” from England (, lets farmers literally “cover their fields,” as the reporter suggested. The tunnels guard against rain, wind, hail, frost and even disease. They also provide support for shade cloth and bird netting.

Although pricey -- $26,000 to $28,000 for one acre -- Haygrove Tunnels quickly pay for themselves by extending the growing season in spring and fall, and increasing yield, quality and income, while reducing chemical and labor costs, growers say. In fact, the tunnels have eliminated the use of soil fumigants such as methyl bromide on strawberries. Haygrove has 220 acres of small fruit and flowers -- 55 acres certified organic
-- covered by the tunnels at its farm in England. Worldwide, Haygrove Tunnels now cover more than 4,000 acres in 12 countries.

Melanie and I have been dying to see Haygrove Tunnels in person ever since Lynn Byczynski wrote about them last year in her Growing For Market newsletter Unlike our little hoophouse and two larger “ high tunnels” that you have heard us sing the praises of, Haygrove Tunnels let producers grow under cover by the acre -- or by the hectare! Our largest structure, a 30- by 96-foot high tunnel, covers only 2,880 square feet. Together, our structures cover just 6,240 square feet, or about one-seventh of an acre.

So, soon as we heard about a Haygrove field day at Steve Groff’s Cedar Meadow Farm ( on Aug. 3, we decided to go. It was well worth the 180-mile round-trip drive to western Lancaster County.

Groff raises vegetables and field crops on 175 hilly acres about one mile east of the Susquehanna River. To reduce erosion, improve water quality and reduce chemical use, he has pioneered what he calls a “Permanent Cover Cropping System” that includes no-till, cover crops and crop rotation. Groff is in his second year of using Haygrove Tunnels. He has six inter-connected bays. (At least three adjoining tunnels are needed for structural strength.) Each is 24 feet wide and 300 feet long. Together, they cover about one acre.

The results at Groff’s farm are nothing short of phenomenal. For example, despite the early arrival of late blight in the eastern United States and Canada this summer, Groff’s tunnels yielded more than 1,800 boxes of tomatoes (by Aug. 16) -- 80 percent of them grading out at No. 1. His unprotected fields yielded only about 40 percent No. 1s.

In addition to doubling yields of top quality tomatoes, Groff’s Haygrove Tunnels have reduced the farm’s fungicide use by more than 50 percent and allowed harvest to begin two to three weeks earlier.

The tunnels also extend the growing season well into fall. Workers at Groff’s farm used to go home to Mexico around the time of the first frost. Tomato harvest from the tunnels last year lasted until Nov. 3, three weeks later than from outside.

“We’ve really fallen in love with the Haygrove Tunnels,” says Farm Manager Chad Wayne. “Crop quality is excellent.”

Unlike more traditional high tunnels, Haygrove Tunnels are only 3-season structures. They are not designed to be used through the winter or support any snow or ice accumulations. A single layer of greenhouse poly is secured with ropes and clips. Sides and ends can be completely opened for ventilation. The poly can also be vented up to the ridge to prevent excessive heat build-up. At the end of the season, poly is removed by bunching it in the gutters where tunnels connect. Greenhouse film is wrapped in black mulch plastic and secured with twine.

Also, Haygrove Tunnels require no excavation or site leveling. In fact, naturally sloping ground is often put to use -- with tunnels running up and down hillsides -- to take full advantage of naturally occurring air movement, says Ralph Cramer, who introduced Haygrove Tunnels to the United States a few years ago.

Cramer raises 50 acres of cut flowers in Elizabethtown, PA (www.cramers
). He first chanced across the tunnels in a magazine article. After visiting England to see the tunnels in person, Cramer said Haygrove invited him to introduce them to the U.S. market. He is now Haygrove’s eastern regional manager in the United States. So far, Cramer has sold tunnels to growers from Hawaii to Nantucket Island in Massachusetts.

“The man in Hawaii is growing watercress in tunnels. He is on the rainy side of the island, where it rains too much. Watercress grows in water, but it can’t take too much rain,” says Cramer.

There is a definite learning curve when growing under cover. “For example, I had to learn what flowers sell for more money,” explains Cramer. He has about one acre of tunnels at his farm.

Here are some other features that set Haygrove Tunnels apart from traditional high tunnels:

They do not need lumber for hipboards on roll-up sides or baseboards.

The tunnels are more easily accessible to field equipment because of their larger size and ends that open completely.

Y-shaped legs are tipped with an auger or ground screw to keep the structure from lifting out of the ground, as sometimes happens with free-standing high tunnels.

After his tunnels were buffetted by Hurricane Isabel in 2003, Groff added extra ground anchors at the ends of his tunnels. He tied the tunnel frames to the anchors with heavy-gauge wire. Although heavily vented frames have withstood wind gusts of up to 70 mph, Haygrove recommends removing greenhouse poly when hurricane force winds are expected.

“We copied Haygrove’s method of producing strawberries and covered the soil (beds, walkways and leg rows) with black weed barrier landscape cloth and cut holes for the transplants,” says Groff. “The landscape cloth not only eliminates all weeds, it reduces condensation inside the tunnels. We like it so much that it will be a permanent addition to our program. At the end of the season, we’ll remove the plant trash and leave the stakes in place for next year.”

Groff transplanted Mountain Spring tomatoes into the tunnels on April 20 this year. The plants were spaced 20 inches apart in raised beds on 5-foot centers. There is one stake for every two plants and five to six woven strings. The extra support is necessary because tomatoes in the tunnels grow more vigorously than field-grown plants.

“We got excellent pollination by venting the tunnels on windy days (which helps remove humidity, toughens the plants and restricts their height) and by using bumble bees. We’re not sure how much difference the bees made, since we had plenty of windy weather, but they’re cheap insurance.”

Haygrove now sells “Luminance” THB (thermal heat barrier), a 6 mil, three-year poly from Visqueen. The poly restricts infrared light and cools summer crops by seven to eight degrees. It also diffuses light better so that light penetrates the plant canopy more completely, increasing photosynthesis. Luminance poly costs about 10 percent more than regular greenhouse plastic. Research has shown the poly increases yields by 20 percent in strawberries and 40 percent in lettuce.

Despite the expense, Groff says he expects his tunnels to easily pay for themselves in just two to three seasons.

After returning home, Melanie and I began looking at the potential for growing under cover in our own fields in a whole new light. And therein lies the problem: We quickly identified two sites that would be perfect for Haygrove Tunnels for both vegetables and cut flowers.