Solutions Source: Outdated greenhouses

May 1, 2007

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Gaps in the glazing, sputtering boilers and rotting, moldy benches. If this scenario sounds familiar, it’s time for some greenhouse upgrades. If the list is lengthy, don’t try to tackle it all at once. Make a list of priorities and complete those first. Once the tasks are done, you’ll likely have a lower energy bill, a more efficient operation and a few more bucks on the balance sheet.

“The best action is an informed one,” said Gene Giacomelli, director of the Controlled Environment Agriculture Program at the University of Arizona. “The grower needs to review the situation and determine where the facility is lacking, or possibly where the greatest operational expense is occurring and attack that area. If there are too many areas, the bulldozer may be the best solution, instead of the Band-Aid.”

But if repairs are in order instead of a replacement, there are some important considerations to make first.

Take cover

Examine greenhouse coverings and make sure the house is airtight, said Linda Barnett, vice president of sales at Stuppy Greenhouse Manufacturing in Kansas City, Mo. If necessary, replace coverings and choose the most fuel-efficient option, she said.

When making greenhouse improvements, start with tightening up the structure, depending on the glazing, said John Bartok Jr., professor emeritus at the University of Connecticut.

Clay Crider, president of CriderAmericas in Cedar Creek, Texas, also put coverings at the top of his list.

“Definitely start with the coverings,” Crider said. “Choose whatever gets the best light for your situation.”

Schubert Nursery in Salinas, Calif., has reskinned several greenhouses in the last few years, said Mike Faigle, president at Schubert.

“We replaced a lot of old fiberglass, which wasn’t getting the full amount of light needed, with single-layer polycarbonate,” Faigle said. “We would have put on twin wall if we’d known gas prices would get so high.”

Other covering considerations include shade systems and energy curtains.

Some growers are installing two and three curtains, including clear curtains, said Bill Vietas, commercial division manager at Rough Bros. in Cincinnati.

“Some growers are using clear curtains, even on a cloudy day, with a shade or energy curtain above that,” Vietas said.

Schubert Nursery, which grows primarily topiaries, also installed heat blankets as part of its improvements.

Reduce labor

Labor consists of half of the cost related to plant production, Bartok said.

“Upgrade the material-handling systems. Choose something that pays good returns like a cart or conveyor system,” Bartok said.

Make better use of the head house and check space use.

“Old houses usually have inefficient head houses or long benches,” Bartok said. “In the head house, track how you handle materials and consider setting up transplanting benches. In the production house, look at other types of benches such as moveable ones, which increase usable space by 10 to 15 percent or more.”

Schubert Nursery added rolling benches, which increased its growing space by 20 percent.

Material handling tops Vietas’ list, including adding carts, or installing a conveyor system or hanging basket system.

An automated watering system also reduces labor.

“If you’re still watering by hand, consider a boom-irrigation system,” Bartok said. “It’s flexible. It can mist and apply chemicals. Flooded benches are also a good alternative.”

Energy crunch

Since energy prices have been eroding companies’ profits the last few seasons, energy efficiency is a must for an upgraded greenhouse.

“Make sure all your equipment, both summer and winter equipment, is maintained and running at top efficiency,” Barnett said. “In fact, make sure you have a maintenance program in place to keep things running efficiently.”

Energy conservation offers the quickest payback, Bartok said.

“Start simple with measures such as putting insulation in areas you don’t need light like sidewalls, and add weather stripping around doors,” Bartok said.

Replace old thermostats with electronic ones, then examine your heating system. “Generally the life of a boiler is 10 years, and there are a lot of old heating systems in use,” Bartok said.

Alternative fuels such as wood, corn or waste oil may offset rising energy costs, but understand investment paybacks before making a decision, he said.

Greenhouse design can determine energy efficiency.

“Many old houses have low sidewall heights from 6 feet up to 10 feet,” Crider said. “Now sidewall heights are 16-18 feet.”

Different venting techniques can save energy, Crider said.

Tunnel vision

Another option for outdated or inefficient spaces may be a low-cost, low-tech tunnel, said Ralph Cramer, regional manager of Eastern U.S. sales at Haygrove Tunnels.

Haygrove tunnels are primarily a single layer of poly with high ventilation, Cramer said.

“The tunnels offer limited protection compared to a standard greenhouse, but the amount of protection you get for the money is a good deal,” Cramer said.

Peregrine Farm in Graham, N.C., uses Haygrove tunnels in cut flower and tomato rotations.

“Our tomatoes were getting foliar diseases, so we started using the tunnels,” said Alex Hitt, owner of Peregrine Farm. “Then we decided it would work for cut flowers too -- the ones that don’t want to be wet like lisianthus and campanulas. The sides of the tunnels are high, so we get better airflow.”

Hitt starts covering cut flowers in March, and they remain covered until September.

The farm has been using Haygrove tunnels for five years.

“One of the reasons we got them is they’re fast to set up, and if you want to move them to another field, it’s pretty easy to do that,” Hitt said. “The plastic goes on fast and it’s attached with ropes instead of clips.”

For more: Gene Giacomelli, University of Arizona, (520) 626-9566; Stuppy Greenhouse Manufacturing, (800) 733-5025; John Bartok, University of Connecticut, (860) 486-2840; CriderAmericas, (800) 237-1189; Schubert Nursery, (800) 410-7111; Rough Bros., (800) 543-7351, Ralph Cramer, Haygrove Tunnels, (866) 429-4768; Peregrine Farm, (336) 376-6320;

Computer tool aids greenhouse design

USDA Agricultural Research Service developed a free program that helps growers build a virtual greenhouse.

The Virtual Grower is a decision support tool that helps users design different greenhouse styles. Users can build a virtual greenhouse with a variety of materials for roofs and sidewalls, design the greenhouse style, schedule temperature set points throughout the year and predict heating costs for more than 230 sites in the United States. Different heating and scheduling scenarios can be predicted with few inputs.

Use the software to build a new greenhouse or make improvements to an existing house.

Download the software at:

Growers concerned over high-wind tests

Connecticut growers were blown away by new building codes that require 100-plus mph wind tests for greenhouses. The new codes are a result of structural damage caused by hurricanes Katrina and Rita, said Bob Heffernan, executive secretary of Connecticut Greenhouse Growers Association.

Several growers said local inspectors are demanding engineer seals certifying new greenhouses for hurricane-force winds, Heffernan said. And the state building inspector will not budge on the issue. Connecticut Green Industries and the Connecticut Farm Bureau are seeking legislation that would implement a special building code for agricultural buildings.

For more: Connecticut Greenhouse Growers Association, (203) 261-9067;

Intergalactic greenhouse

A Georgia Southern University professor envisions life on Mars, thanks in part to robotic greenhouses that would provide food for future astronauts.

Robert Cook, professor of computer sciences, is experimenting with plants that may survive on Mars.

“The Mars atmosphere is cold, low pressure and carbon dioxide is the major gas,” he said. “But it turns out that plants on Earth like carbon dioxide and generate oxygen. We do have plants that exist in cold, dry conditions, such as cacti and lichens, but we don’t necessarily have a duplicate of the type of atmosphere you’d find on Mars.”

Cook’s experiment includes a vacuum bell jar and a bicycle flat tire kit to add carbon dioxide. He added cactus to his Mars “greenhouse.”

The missing ingredient is a low temperature, he said.

“As far as we know at this point, Mars is a lifeless planet and we have the ability to bring life to it,” he said.

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“Mars is an entire world that we have the opportunity to populate if we can figure out what will grow there. That’s pretty exciting.”

For more: Robert Cook, Georgia Southern University, (912) 681-0892;

- Kelli Rodda 

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Grants relieve some greenhouse costs

Chris Byrnes, president, Viability LLC

Grant money for greenhouse improvements is out there for the taking, but it’s often an arduous task to find.

There’s a lot of diligence involved in going out and finding grant money. We can find the needle in the haystack when it comes to free money.

States often have grants, but typically that information is hard to find.

The feds have a Web site clearinghouse for grants of all sorts at

Growers can peruse the federal site, but it’s overwhelming because of the sheer amount of information.

When it comes to grants, think about specialty projects, energy or environmental plans for your greenhouse. Money is out there for more things on the periphery of your business.

We’ve helped several greenhouses obtain grants for biomass projects, energy-efficiency plans and new products. Last year, the USDA provided more than $17 million in grants for renewable-energy and energy-efficiency projects. The USDA also provided more than $21 million for value-added agricultural products.

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We also have access to private foundation funding, which is another excellent avenue for businesses.

Chris Byrnes is the president of Viability LLC, an economic development and incentive services firm in Holland, Mich., (616) 886-1691;