In Northwest farm country, tiny blueberry buds are already starting to plump up. But cold snaps could kill them. To save more of those fruit-bearing buds, blueberry farmers are currently waging an epic battle against frost.
At Olsen Brothers Ranches outside of Prosser, Washington, there is a retro-looking frost alarm -- like a radio from the 1940s -- that sings to wake workers when frost bites at night. It sends them scrambling from their beds when the temperature drops too low.
Boots on. Up and out to save tender fruit buds.
Farm supervisor Arnulfo Munoz says the alarm is a bit tough on his marriage. His wife is not a fan.
“Oh! Every time she feel the cold outside she says, ‘Oh, the alarm again? Are you going to sleep, or going to let me sleep?’” Munoz says.
Staying ‘one step ahead’ of the frost
A skeleton crew rattles out with the first alarms to drive around the pitch-black fields.
“Cold spots move around on us,” says Keith Oliver, who oversees hundreds of acres of valuable fruit here at the farm. And 800 pickers.
“We have hundreds of thermometers scattered throughout the farms,” Oliver notes. “And people are driving around at night looking at those things after the frost alarms go off. And we have to just keep watching and jumping around and trying to stay one step ahead of it.”
Oliver cares about all he tends: Hops, cherries and fancy apple varieties. But at the moment, his focus is on the blueberries.
“With our organic blueberries right now, we spend the most money per acre growing them and we can make the most money per acre selling them,” he says. “If things go right.”
So they fight frost hard, to yield more fruit.
Timing the battle
Sometimes the frost alarms go off as early as 9 p.m. That means already-worked and tired crews have to head back to the farm for an all-night battle.
“The work in the daytime suffers,” Oliver says. “Because we can’t just bring in extra people. It’s the same people.”
On a really bad, cold night -- here’s the battle plan: workers find the coldest spots, then scramble to start irrigation sprinklers. Then they start waking up even more workers -- phone-tree style. Soon giant wind machines will sputter to life and workers will light up hundreds of propane heaters.
All that usually saves some blueberry buds. But some years all this work doesn’t pay in the end -- if one night is too cold for too long.
Timing the battle cry for the cold war each night is key. If you wake workers up and turn everything on too soon, Oliver says it’s like “burning money.” Thousands of dollars per hour.
If you start the fight too late, you risk major crop-drag.
New science and better tech
Washington State University scientists are amassing data by freezing cut branches from the fields every week in a lab. Then cutting open each bud and seeing what survives different temps. Other Northwest crops already have these precise cold-hardy models.
But the Northwest’s blueberry boom has outrun science. WSU scientist Gwen Hoheisel says it will take 10 more years of data to make a useful real-time model for farmers.
This is Oliver’s 31st spring on this same fertile ground. His blue eyes are mostly blood-shot. Determined. He says with better wind machines and burners and experience, they’re able to save more fruit.
If Oliver and other Washington farmers win the frost war, they’ll likely harvest more than $100 million worth of blueberries this summer.
“We go for it,” Oliver says. “We don’t want to give up on the year in the spring. We’re gonna fight the frost.”
He’ll likely lose much of his crew by battle's end. Even extra pay doesn’t make the job worth it. But come June, those that stick around can sleep in … until around 4.