Grower Chris Lange snaps open a tree glove. It's like a pillowcase that wards off frost. (Sasha Khokha/KQED)
If you’re driving through the Central Valley this winter, you might notice something unusual: rows of what look like white garbage bags planted in the ground.
“They look like white ghosts out here,” says farmer Chris Lange. He’s standing in the middle of a citrus orchard nestled at the edge of the Sierra Foothills in Woodlake, just below Sequoia National Park. All these young Minneola tangelo trees are wearing something called tree gloves.
Lange unfolds one, snapping it open in the wind.
“It’s very simple,” he explains. “It’s a nylon material and it’s stitched. Just as a pillowcase would be, it’s open in one end. You put the pillow slip over the tree, and put a drip sprinkler inside.”
That makes a little wet microclimate around the tree. The mesh gloves trap the heat and the moisture, potentially saving growers water and the cost of losing frostbitten trees. Lange says that, according to his thermometer, the gloves can warm up the baby trees by about 4 degrees.
“That doesn’t sound like that much, but if you’re right on the edge of freezing that could make quite a difference,” says Lange. “The real test will come when we have an arctic blast that would be enough to not only burn the trees, but kill them.”
Devastating freezes in 1998 and in 2007 wiped out acres of trees in Tulare County, the heart of the San Joaquin Valley’s citrus belt. The tree gloves were designed by a trio of 20-something brothers, whose own family farm just north of here was hit hard by a citrus freeze two years ago.
“They cost less than a dollar apiece to save [farmers’] investment in their crops, their livelihood,” says Anthony Flores, a sales manager at the store in Woodlake. “Last I’ve seen, we probably had about 10,000, and they went that same day. They were a hot commodity."
Homeowners are catching on to the trend, too, says Flores. They’re starting to buy the gloves to put over their bougainvillea and other garden plants -- to protect them from frost.
Now researchers are testing whether the gloves can work to prevent the spread of Asian citrus psyllid, a pest that could be a major threat to the state's $2 billion citrus industry.