GRAND RAPIDS, Mich. (WOOD) — With apple blossoms reaching full bloom, a frost expected overnight could threaten apple orchards across West Michigan.
Between full bloom and petal fall, apple blossoms can be killed when the temperature dips below 30 degrees, so local growers worked Sunday to keep their orchards warmer than that.
Nick Schweitzer, a fifth-generation apple grower in Sparta, spent the day cutting his orchard’s grass so it would absorb as much of the sun’s heat as possible.
“When the grass is cut down, that’ll help allow the sun and the ground to absorb the solar radiation from the sun, which could potentially give us a max two degree bump in temperatures overnight,” he explained.
He said that two degrees could be crucial in keeping the blossoms alive, as the overnight temperatures are straddling the fence of the 30-degree threat.
Schweitzer also irrigated the lawns to draw heat from the ground. Water released from the ground is around 50 degrees. When that meets the air, it heats up the ground.
Apple growers also use frost fans to circulate heat in their orchards, keeping naturally-rising heat moving from the tops of the branches toward the ground.
In 2012, an early warm-up in March was followed by a frost in April that devastated the state’s apple crop.
But this year’s weather hasn’t been so dramatic and Schweitzer hopes this frost won’t be too bad. He doesn’t expect a disaster similar to the one in 2012. He said that at this point, losing some blossoms won’t ruin the entire crop.
“We only need about 10 percent of the flowers on a tree to give us a full crop. We can stand losing a little bit of those flowers and not have it be a big deal,” Schweitzer said. “If sticks around 30, it shouldn’t be too bad.”
Experts say you can loosely cover smaller apple trees to protect the blossoms. Be sure to take the cover off after the sun rises.