Enjoy fresh produce year-round using a hoop house
By Jim Sloan
With this winter’s mild weather in Nevada, some gardeners are wondering if they should have tried growing vegetables right through the cold season.
Of course even with the dearth of snow and warm mid-day temperatures we’ve experienced in December and January, vegetable gardening in the winter is usually out of the question — unless you have a hoop house.
Hoop houses, also called high tunnels, are an unheated, plastic-covered version of a greenhouse. They are typically easy to build and inexpensive, and by collecting the sun’s warmth and protecting plants from bitter winter wind, they can help extend the growing season by as much as two months, according to University of Nevada Cooperative Extension expert Holly Gatzke.
Gatzke, the Extension Educator for Lincoln County, has been studying hoop houses and helping farmers install them since 2007. She’s conducted field trials on working farms in Lincoln County, and enjoys bringing skeptical growers into one of her hoop houses in the middle of winter.
"They walk in out of the freezing cold and see these flourishing plants and they can’t believe it," she said.
How Cooperative Extension helps farmers, tribes
University of Nevada Cooperative Extension faculty have helped farmers throughout Nevada discover the benefits of hoop houses. In Lincoln County, hoop houses have helped growers expand a prospering market for specialty fruits and vegetables sold at farmers markets and to high-end Las Vegas restaurants.
"A lot of our farmers were struggling financially with traditional alfalfa production and cow-calf operations while at the same time nearby Las Vegas was craving locally grown fruits and vegetables," Gatzke said.
"So we set up field research plots, workshops and seminars that helped these farmers go from growing alfalfa to producing very high-quality products for chefs in Las Vegas. Hoop houses were a big part of that."
Although some farmers resisted the transition from traditional alfalfa farming to niche farming in hoop houses, other farmers happily embraced hoop houses, Gatzke said. One of those growers was Shannon Simpson of Pioche, who built a hoop house with Gatzke’s help and now produces lettuce, tomatoes, radishes, beets, peppers and flowers despite the area’s "hellacious winters."
Gatzke’s 2009 study, "Plant Season Extension in the Desert," provides valuable design guidelines for gardeners and farmers considering planting in hoop houses. In it, she notes that unheated hoop houses generally don’t allow year-round agriculture but that they have extended the growing season in places like Colorado by as much as 110 days.
Gatzke and Cooperative Extension Educator Carol Bishop in Logandale, Nev., conducted a study in 2010 to determine the costs and benefits of hoop houses and found that the structures can help pay for themselves if a commercial grower selects the right plants and successfully sells the produce at farmers markets or to chefs.
Cooperative Extension’s Federally Recognized Tribal Extension Program has also helped construct hoop houses with the Yerington, Walker River, Duckwater and Ely tribes. Reggie Premo, a program facilitator with Cooperative Extension who works with Native American farmers and ranchers, said the goal is that the community-maintained hoop house crops will produce healthy food and promote healthier living on the reservations.
"If we can reduce the negative impacts of processed food, we can reduce obesity and sickness and provide for a sustainability for all in the years to come," he said.
The ins and outs of hoop houses
Hoop houses can also make sense for amateur gardeners.
UNCE water quality specialist Sue Donaldson said a hoop house can be as small as 4 feet by 6 feet, or as large as you want. Most are made with a rigid frame made of piping and are covered with 6-mil, ultraviolet stabilized plastic greenhouse film. The plastic cover has a lifetime of a few years, depending on the amount of abuse from wind, snow and other sources like curious dogs or critters.
A well-placed, carefully installed hoop house allows you to start growing crops and plant starts earlier in the spring, and can give you a month or two of freeze protection in the fall, Donaldson said. If you grow cold-tolerant crops like lettuce and spinach, you may be able to produce them year-round. You can also try new varieties that need the longer growing season provided by hoop houses.
"If you’ve ever lost a crop of vegetables to early or late-season frosts -- or like me, to an unexpected July freeze -- you might consider installing a hoop house," she said.
Hoop houses also provide some protection from wind and pests or diseases. Vegetables grown in hoop houses have noticeably fewer blemishes, Gaztke said.
Unlike a greenhouse, which may require building permits and foundation work and could affect your property tax rates, hoop houses are considered temporary structures. They’re much less expensive, but also less durable than greenhouses.
"With planning, you can make your hoop house movable, and relocate it to different parts of your yard if desired," Donaldson said. "You can design or build your own hoop house, or purchase a kit. Free plans are available online."
Considerations to make before installing a hoop house
Before you install a hoop house, Donaldson advises that you consider how you’re going to grow your plants. Will you plant directly into the soil? In this case, it’s easier to amend the soil with organic matter before you start construction. To determine what the soil needs, have a sample analyzed. Call your local Cooperative Extension office for a list of commercial soil labs.
While it’s most common to plant directly in the ground, some gardeners place their hoop houses directly over existing raised beds. Containers can also be used. Make sure they have adequate drainage, and consider the potential for heat loss from containers placed above the ground, Donaldson said.
Since hoop houses rely on passive solar heat and ventilation, Gatzke noted that they’re much less expensive to operate, but don’t provide the same level of protection for tender crops as a greenhouse. She advises adding floating row covers for an extra layer of protection over your plants when the temperature really drops. In the heat of summer, many growers replace the hoop house’s plastic cover with a shade cloth, but in cooler areas, gardeners simply need to raise the sides of the plastic to allow better ventilation.
Hoop House (High Tunnel) Information and Plans