How ice can actually protect strawberries from freezing
Florida farmers form a layer of ice around their tender strawberry plants on purpose.
Florida farmers rush to save strawberry crop from freezing weather
FOX Weather multimedia journalist Brandy Campbell reports from Dover, Florida, where farmers are using water to hopefully save their crop from freezing temperatures expected there tonight.
Believe it or not, Florida strawberry farmers use ice to prevent their berries from freezing. Many have sprinklers going non-stop over the fields while temperatures are near or below 32 degrees, like they did Sunday morning. The goal is to create a thick layer of ice over the plant.
"If we didn’t protect the flower or the fruit we have out there, it would damage the fruit to where we couldn’t market it," said Matt Parke, Operations Manager of Parkesdale Farm. "We’d have to throw it all on the ground."
Parke was up all night protecting his fruit from frost and freezing. FOX Weather’s Brandy Campbell caught up with him Sunday in Dover, Florida.
"We’d lose our whole crop," said Parke. "In a matter of minutes, it could cost us millions of dollars."
How does ice stop berries from freezing?
Water molecules give off heat when they freeze, going from liquid to solid form. As long as liquid water continues to freeze, the energy/heat will be released keeping the berry and blossom from dropping below 32 degrees.
Sap in the plant is water mixed with sugar and freezes below 32. So, the plant is not damaged.
A layer of ice protects this strawberry crop in Plant City, Florida.
(TONY RANZE/AFP via Getty Images / Getty Images)
We are all familiar with the opposite, the latent heat of vaporization. Remember getting out of a pool in a breeze and feeling chilled as the water evaporated off your skin? Water molecules require an input of energy/heat to go from liquid (drops of pool water) to vapor.
Extra heat/energy goes into breaking the molecular bonds holding water molecules in liquid form. The opposite is true when liquid freezes. Water molecules release energy/heat to freeze into crystals. That heat keeps the fruit and flowers at a constant 32 degrees.
Florida deep-freeze
Parkes’ berries are accustomed to a high of 75 degrees and a low of 50 during the month of January. But, the farm dropped to 32 degrees for hours on Sunday morning.
The same chill brought unseasonably low temperatures to other parts of Florida as well. Marathon (the Keys) bottomed out at 46 breaking the previous record low set in 1955 by three degrees. Sunday was the coldest morning in Miami in over a decade.
(FOX Weather)
The National Weather Service issued Freeze Warnings and Frost Advisories for much of the state through Monday morning. So it looks like another sleepless night for Parke.
(FOX Weather)
WHAT'S THE DIFFERENCE BETWEEN FROST, A FREEZE AND A HARD FREEZE?
Plant City and neighbor Dover earned the nickname "Winter Strawberry Capital of the Word" a century ago when the railroad was extended to Tampa. This allowed growers to export the winter strawberries along the east coast.
FLORIDA’S WINTER STRAWBERRY SEASON BERRY DEPENDENT ON WEATHER
According to the U.S. Department of Agriculture, Florida grows nearly all the nation’s winter strawberries. While California produces 90% of the nation’s strawberries annually, the Golden State is too cold in winter for a booming crop. Florida weather provides the perfect conditions to supply the U.S. The Sunshine State produces 8% of the berries a year.