Courtesy University of FloridaHigh tunnels, also called hoop houses, can extend the season and protect crops from weather.High tunnels, also known as hoop houses, have exploded on the scene growing from a few acres the past decade to more than 1,500 acres.
The Quonset-hut-like structures are sometimes referred to as “poorman’s greenhouses” and consist of a frame—typically metal poles—over which plastic sheets have been stretched.
Blueberries, strawberries and peaches are some of the crops grown in high tunnels, and some growers have expanded into tomatoes, peppers, miniature peppers, okra, cauliflower and melons.
Squash that, in the past, had to be imported during December through February now can be produced in tunnels, enabling growers to get top dollar, says Dan Cantliffe, county Extension director for the University of Florida’s Institute of Food and Agricultural Sciences in St. Johns County.
High tunnels serve many purposes.
They protect crops from cold weather and can eliminate the need to run overhead sprinklers during freezes, saving money, product and water, Cantliffe says.
Tunnels prevent “rain check” or water marks on tomatoes that can occur during rainy weather and interfere with ripening.
High tunnels also help growers control the timing of their crops and help ensure consistency, says Bob Hochmuth, multi county Extension agent for the Suwannee Valley Agricultural Center in Live Oak.
In addition, they allow growers to produce a high-quality crop at a time when they otherwise could not. This can help growers gain a better market position, primarily by starting their harvests earlier, he says.
Today, there is “broad statewide distribution of usage and technology that was minuscule three years ago,” Cantliffe says, largely because high-tunnel technology has improved and their costs have dropped.
Developers now are looking at heavier gauge plastic that resists weather, diffuses light, reduces ultraviolet light and heat, and even has qualities that stop fog that forms under the plastic from dripping onto plants, he says.
Production costs increase when you grow in tunnels, Cantliffe says, but the higher yields and returns from improved marketing timing can offset the initial costs.
Many growers reduce pesticide use and use biological controls instead, saving money on chemical inputs.
Tunnels typically range from about 50 cents to $2 per square foot—or about $20,000 to $80,000 per acre—and are about 30 feet by 180 feet, Cantliffe says. He recommends that they be 14 to 16 feet high to allow room for hot air to disperse.