In 2012, an estimated 1.7 million households in the US purchased greenhouses, compared with 800,000 in 2000, according to the National Gardening Association. Sounds like a big jump. But Bruce Butterfield, the association's market research director, offers perspective: That still represents only about 1 to 2 percent of gardening households. "Of course, there are greenhouses," he adds, warning consumers away from "rickety" models that have flooded the market in the last few years. They're made of cheap materials and often have no foundation.
"It's like heating the outdoors," says Butterfield, who recommends kits that offer "some fairly rugged barrier that separates frozen ground from nonfrozen ground."
"While you may be a fairly skilled gardener out of doors, you've got to become an elite gardener to grow in a greenhouse," he says in an article on Philly.com. "You've got to control the temperature, the moisture, soil, ventilation, hours of light and sometimes, pollination," he says. "I think it's tricky."
