If you’re a smaller operation just getting into tunnels and don’t already have fumigation equipment, you’ll probably want to adopt a soilless culture, such as coconut fiber bags or containers filled with composted pine bark.
Location also is important to ensure proper airf low, Cantliffe says.
“If you’re in a situation that doesn’t have airflow, you’ve got a problem,” he says.
So don’t set up your high tunnel in an area surrounded by buildings or in a valley that could get cold or wet.
When setting up a high tunnel, Bethea advises growers to “adapt to fit your environment.”
A common mistake growers make is building a tunnel too long. He suggests a maximum of 300 feet.
Bethea also recommends a north-south orientation. An east-west orientation under Florida‘s winter sun can bake crops on the south side and slow maturity on the north side.
“Ventilation strategy is important,” he says.
If you just put a plastic roof over your tunnel, “you get convective heat buildup, like an oven,” Bethea says.
He actually builds an “attic” in his tunnels to shield plants from the heat.
The higher the better, he says. Bethea’s tunnels are up to 14 feet high.
He also includes rain gutters, up to 80 inches long.
Altogether, Bethea estimates his tunnels cost about $30,000 to $100,000 per acre.
“It’s worth the investment to be able to handle the adversities and be consistent,” he says.