December began with weather so chilly, Mary Beth Locke had to run her sprinklers to keep her crops from freezing to death. Local frost warnings last week had Jonathan Squires rushing to wrap his plants with frost blankets to insulate them from the most brutal temperatures. Florida’s lack of snow doesn’t mean frost and freezes are impossible here. These conditions exist and they can damage or destroy crops, requiring farmers to fight the elements to keep their products safe for the consumers they serve in and around The Villages. Squires, a vendor at the Brownwood Farmers Market who cultivates ornamental plants and herbs at his Leesburg nursery, Just Perfect Plants, wrapped his cold-sensitive plants in frost blankets to prevent frost and freeze damage on the coldest nights.
“You’re basically putting a coat on (the plant),” he said. “You lessen the air flow because you’re developing like a greenhouse.”
Homeowners with sensitive plants in their gardens can use blankets, sheets or towels to cover them from the cold. To protect the plant, the covering must extend to the ground to trap radiant heat, according to the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS).
But some people take Squires’ analogy literally and try using winter coats to keep their plants warm.
He said it works. One person told him she planned to give away her old winter coat before successfully using it to keep a plant warm on a cold night.
But there are cases when wrapping or covering plants won’t offer the necessary insulation.
Locke, who operates Back Road Berries in Oxford, needed to run her sprinklers on her strawberry plants on the morning of Dec. 1, when her farm experienced a low near 32 degrees Fahrenheit. That’s the minimum temperature for conditions that can cause plant tissue to freeze.
“We had a freeze warning, and it actually did freeze,” she said. “What it does, the sprinkler forms a layer on top of the plant. You can’t turn the water off until the ice melts.”
This freeze protection method ices in berries to insulate them from chilly air. Citrus growers also do this to protect their oranges.
Farmlands are more vulnerable to freezing temperatures than suburban areas because they’re less likely to have materials like asphalt to generate additional heat around the area, Locke said.
Some farms try to work around that challenge by using enclosed spaces for growing.
An enclosure called a high tunnel allows farmers to grow crops without exposing them to destructive elements, said Matt Smith, sustainable agriculture and small farms agent with the University of Florida Sumter County Extension Office.
These enclosures protect plants by increasing air and soil temperatures and shielding from wind damage, according to UF/IFAS. High tunnels may range in height from 8-20 feet high.
Temperature drops keep farmers busy no matter what they’re cultivating.
Kris Sutton of Sunsational Farms in Umatilla said it hasn’t yet gotten cold enough to run sprinklers on his citrus groves, but he’s wrapped plastic around the sides of greenhouses holding tomatoes and peppers to maintain warmth.
“It’s the same plastic that’s on the roof, we just have more of it around on the sides to keep it warm,” he said.
UF/IFAS advises people to only use plastic for cold protection when supported by frames or hoops, such as in a greenhouse or high tunnel. Wrapping plastic directly on plants can move heat away from it and increase cold damage.
Farmers are keeping a closer eye than previous seasons on crops that face the risk of cold damage during the winter because of previous financial losses due to COVID-19, Smith said.
That’s especially true of blueberry farmers, Smith said. Their last season peaked at the start of the pandemic, when Florida had a stay-at-home order in place.
“They want to make sure they have a really good crop for next year,” he said.
Blueberry plants actually need the cold to grow. Each variety of blueberries requires a certain amount of time in temperatures spent below 45 degrees — often referred to in the industry as “chill hours” — to generate its blooms.
It’s when the fruit starts to develop that blueberry growers need to be concerned, said Ryan Atwood, a blueberry grower in Umatilla.
“We don’t start worrying about cold protection until January and February,” he said. “Up until then, we’re all for the cold weather, particularly early in December.”
Senior writer Michael Salerno can be reached at 352-753-1119, ext. 5369, or firstname.lastname@example.org.