December 2007 Issue

People in Glass Houses

Alice Pitts has been an avid gardener for as long as she can remember. But it was a man-made object, not a collection of plants, that motivated her to build a greenhouse on her and husband Tom’s 12-acre property in South Newbury, in Geauga County. That object was a hundred-year-old glass door that the couple picked up for $25 in 1995 — framed in an arch of poplar and flanked by a transom and sidelights — that once provided entry to a local estate greenhouse.

“Finally, I said to my husband in 2005, ‘We are either going to sell this door, or we are going to use it,’” the 74-year-old Pitts, an accountant for the city of Beachwood, recalls.

While the 12-by-24-foot structure that now graces her garden may have started as a frivolity, it definitely has practical benefits. Instead of spending $1,000 every spring on annuals, Pitts and her husband, a retired die maker, start their own and “winter over” container gardens and tropical plants such as mandevillas. Then there’s the opportunity to be around green, growing things every day of a long, cold Ohio winter. “It’s very therapeutic for me,” she says.

Today’s residential greenhouses — conservatories, as the high-end ones are called — run the gamut from elaborate custom jobs with raised beds and automatic watering/misting systems to a utilitarian stand-alone structure built from a kit that doesn’t require a foundation. The increased variety has made that little piece of eternal spring available to more people, even in an era of sky-high energy costs. “Today’s greenhouses are certainly a lot more efficient and well engineered than they were, say, 10 or 15 years ago,” says B.J. Thomas of Rockford Corporation, a distributor of greenhouse kits based in Mentor. What homeowners build depends not only on their budget but also their preferences and needs, whether it’s simply starting seeds in the spring or maintaining an exotic collection of tropicals year-round.

The first decision gardeners face is settling on the size of greenhouse they’d like to build. That typically means thinking about a structure that will accommodate the plant collection they have or would like to acquire. Most people go with a single-aisle greenhouse — one with a walkway down the middle, typically with benches or raised beds on either side —10 or 12 feet wide, according to Jeff Kenyon of Arcadia GlassHouse, the Painesville-based concern that built the Pitts’ greenhouse.

He notes, however, that an increasing number of clients want enough room to add a table and chairs, in some cases even more seating for entertaining. Others are looking to install a koi pond, waterfall or “wet wall” on which certain types of plants can grow. But Pat Long, residential and commercial division manager for Rough Brothers Inc., a high-end conservatory builder in Cincinnati, stresses that it’s definitely not the place for fine furnishings, high-end electronics — anything, in fact, other than outdoor furniture. “It’s going to be very moist and humid,” Long says. “You’re trying to create an outdoor environment enclosed in glass.”

The next decision to be made is where to build the greenhouse. Kenyon points out that while a detached greenhouse can serve as a wonderful focal point for the backyard or garden, an attached counterpart is more energy efficient and easily accessible to utility lines. Perhaps more importantly, it doesn’t require a trudge through the snow to enjoy. However, it generally must meet tougher foundation requirements and may necessitate some modification to the home. He advises against putting a greenhouse on the north side of the house unless it’s specifically intended for growing plants requiring lower light levels (such as orchids or Thomas African violets.)

Conversely, the much-ballyhooed south side actually exposes many plants to too much light and heat, a situation that can be remedied by using a glass containing a clear shading coefficient to screen out a percentage of the sun’s rays. Shades — Thomas says the newest ones are made of a vinyl-coated open-weave fiberglass material that offers opaque coverage, a vast improvement over traditional shade cloth — provide supplemental protection in the summer.

“We’ll even put one side of the greenhouse at a higher shade level than the other to create microclimates in the greenhouse,” Kenyon says. “Most of my customers want to be able to grow orchids on one side and tropicals on the other.” 

When it comes to finding a covering for the frame, the best material, in terms of both quality and insulation, is double-pane glass. Less expensive and less energy efficient is single-pane glass, which Thomas says is found in some greenhouse kits. Cheaper still is polycarbonate, a plastic that Kenyon says is equal to double-pane glass in energy efficiency but 200 times stronger. Although the Pitts chose double-pane glass for the walls of their greenhouse, they went with polycarbonate for the roof. “We live in a wooded area,” Pitts explains. “We thought, all we need is one little branch to fly across the roof, and we’ve got a broken pane.”

Kenyon says the style of greenhouse should complement that of the house. At the very least, Long concurs, it should reflect elements or materials in the house’s exterior — for example, the same roof pitch, a matching brick or stone knee wall, a matching powder-coat paint for the frame, similar doors, hardware and trim. “Just a few little accents to that greenhouse really makes it feel like it’s part of the home,” Kenyon says.

Even more important, from an operational standpoint, are the heating and cooling systems. While less-expensive electric, gas and propane heaters are available, Kenyon and Long prefer integrated hot-water radiant systems. The cooling and air circulation provided by vents and fans can be augmented by an evaporative pad system that consists of what Kenyon describes as a large “wet sponge” located on one side of the facility and an exhaust fan on the other. “You’re basically pulling a block of moistened air across the greenhouse at crop-level height,” Long explains. Computerized environmental-control systems are available to regulate it all, right down to opening and closing vents and lifting and lowering shades.

“Some of my customers go to Florida in the winter for extended periods, and we set these greenhouses up to run on their own,” Kenyon says. “They’re virtually maintenance free.”