KEMPTON, Pa. — In the back-and-forth battle of Man vs. Mother Nature, Scholl Orchards has a new ally in the fight against frost.
It’s now Man and Machine vs. Mother Nature.
Scholl Orchards, a fourth-generation family business, on Thursday installed wind machines to protect up to 45 acres of its fruit crop at its orchard in Kempton, Berks County.
It's not taking a chance this year on a repeat of what happened last spring.
- Scholl Orchards stood up wind machines for the first time Thursday on its land in Kempton
- The machines are designed to raise temperatures in the orchard and prevent frost damage
- Without them, a year's worth of work could be lost in a night
“Our crop was reduced significantly last year,” Jake Scholl said in a phone call back in the middle of January (a touch-base during a month that would turn out to be the Lehigh Valley’s warmest January on record).
With 65 acres of fruit trees to tend, the Scholls were “fighting Mother Nature tooth and nail” in 2022 as the early unseasonable warmth caused their trees to start to break dormancy in the winter.
“And then it got cold and we had a lot of frost and freeze issues,” Scholl said. “And we grow varieties that can handle the cold. We can handle some damage on a peach tree … we only really want 15 percent of the flowers that are there.
“But you have five or six events in the early spring where temperatures drop below freezing and it just keeps shaving off another percentage, another percentage.”
And so the Scholls — who operate Scholl Orchards in Bethlehem — looked west to places such as Washington state, where there’s long been a wind machine season tucked inside of the growing season.
“The machines blow air around so it doesn’t settle,” Scholl explained.
They’re also much more efficient and have largely replaced the old smudge pots that were used to burn heating fuel to warm the orchards.
Now the wind machines tower over their land – not to disturb the views, but to protect their investment and the family business.
‘Half a degree is a lot in our world’
There are two types of freezing weather conditions that can affect crops such as those the Scholls grow — advective and radiational.
Of the two, the more challenging is radiant frost brought on by a process at night known as radiational cooling. It allows the heat absorbed into the ground during the day to rise again at night and escape into the atmosphere.
The process is much more pronounced when you have a clear sky, according to the National Weather Service, leading to a rapid drop in temperatures near the surface, which causes frost to accumulate on plants.
That’s where the new wind machines will come into play.
They’ll take the warmer air rising from the ground that gets trapped in what’s known as an inversion layer and mix it back into the crop zone, hopefully bumping up temperatures 3 to 5 degrees.
Under the right circumstances, it’s more than enough to prevent frost from forming and pulling moisture from the fruit buds, dehydrating them and causing lasting damage.
“I think 3 to 5 is a real strong number,” Scholl said in a phone call Friday morning. “What people don’t understand is that half a degree is a lot in our world. Half a degree is huge. So if I can get 3 or 4 degrees out of these, I’ll be ecstatic.”
The protection now offered is critical as the trees go through different growth stages.
"Half a degree is huge. So if I can get 3 or 4 degrees out of these, I’ll be ecstatic.”Jake Scholl
“It starts with the buds swelling. And then they start to show a little pink, which is when the flower starts to show, then you have your full bloom, and then you have your petal fall, which is when the flower kind of falls apart. But there’s different thresholds of temperatures that each stage can handle.”
That means it's particularly crucial because of the elevation change in the orchards that the sensor on the machine knows the right moment to power it on.
“A lot of times to us, maybe they're calling for 28 degrees but it could be 24 out here [in Kempton] right? So there's a sensor on a 50-foot cable and you kind of get it away from the machine because the machine puts out heat,” Scholl said.
“So there’s a sensor that will turn them on at the temperature that I feel I want it to go on at. Because maybe you have times where it's dead calm, and at top of the hill it’s 30 [degrees] but the bottom of the hill is 26. And as you walk down that hill, you can feel it.
"So at the top of the hill you can have a full crop. At the middle of the hill, you could have half a crop and at the bottom, you could have nothing. So half a degree or a degree or two, it’s huge.”
Necessary frost protection methods
While there’s a science and precision behind these wind machines that should help to ease the anxiety of a frosty night, Scholl said he still can’t sleep when just one cold night can ruin a year’s hard work.
“I don't really sleep well to begin with,” he said. “And I don't sleep when it's like that," meaning below freezing.
There also are other frost protection methods and various costs — both literal and physical — the orchard will employ.
“We have to have these propane-powered tanks, they're called frost dragons,” Scholl said. “And they go on the back of a tractor, they're pretty dangerous. They’re just dangerous to run at night on the hill. We're still gonna run two dragons in parts of the orchard that these heaters don't cover.
"And another thing we started doing, too, is there's a material called Surround. It's a clay substance, it's bright white and we put it in a sprayer, like a tree sprayer. It’s organic.”
But these ways to get in front of frost damage are not without questions from the public, and Jake Scholl is happy to provide an education on why the methods are needed.
“Every ton of fruit that these machines save is one less time it has to get trucked from 2,000 miles away."Jake Scholl
“We sprayed the trees white yesterday, and I checked this morning," he said. "And that's just to reflect sunlight. It's a southern slope behind my house. And the plum trees are the first to bloom and they're starting to swell up.
“So you know, the trunks of the trees are all painted with permanent paint to keep that trunk from heating up during the day… there's so many things we're doing. You know, we don't prune certain things because that takes the heartiness out. We're hitting it on a lot of angles.”
But Scholl said he also is frustrated about the public’s concern — through the lens of social media — of the wind machines being powered by propane and raising temperatures over wide swaths of land, not to mention a presumed impact on wildlife.
“There’s a lack of education — we all know that,” Scholl said. “But for every ton of fruit they save — and it’s literally tractor-trailer loads and pounds of fruit that we could produce — it’s one less load of fruits or vegetables that has to come from Washington or California. Right?
“Every ton of fruit that these machines save is one less time it has to get trucked from 2,000 miles away. It's $23,000 just in shipping costs per trailer load right now.
"So think about that, because people don’t realize … they think we’re out here killing birds and honey bees [which are diurnal and don’t fly at night while the machines are operating].
“But in all reality, those wind machines are saving a tremendous amount. They’re saving a tremendous amount of fuel and they’re literally saving our fruit.”
