With their harvests underway, Skagit County farmers are learning how the hot and dry summer — including record-breaking heat — affected their crops.
Some have reported smaller yields of cool-weather crops such as potatoes and spinach seed, while many corn and grain crops fared well. Skagit berries seem to have been spared from the worst of the heat in part due to cooler, maritime weather.
After a record-breaking heat wave in late June, Washington State University Skagit County Extension Director Don McMoran said he predicted crop yields would be down 10% across the board.
“I have to eat my words because the grain crop was tremendous this year. It really liked the drier, hotter weather,” he said. “But I would say for other crops, there was definitely an impact.”
Potatoes, the county’s most valuable crop that brings in $60 million a year for producers, took a hit.
Darrin Morrison, with Morrison Farms south of Mount Vernon, said when temperatures climb above 90 degrees, potato plants can stop growing. He estimates potato yield is down about 20% this year.
“There are not dramatic differences, but there are differences,” he said.
Crops fared well in areas with adequate soil moisture, Morrison said. On the other hand, crops were more stressed in drier fields and those that are difficult to irrigate.
McMoran said higher potato prices could help make up for some of the yield loss this year.
With the potato harvest running through late fall, it’s too early to know the full impacts of the heat.
Morrison said Skagit Valley farmers have an advantage because they grow a diversity of crops, and growing conditions often vary from field to field.
“A good year there is a bad crop, and a bad year there is a good crop,” he said.
Another crop stressed by the heat was spinach seed, a lucrative crop for county growers.
Todd Johnson, a Skagit County grower of vegetable seed, said he estimates spinach seed yields are down 15% to 20% due to dry weather and warm temperatures.
“It could have been worse,” he said. “We fared much better than places like the Willamette Valley in Oregon because they sustained 100- to 110-degree temperatures day after day.”
Johnson’s yields of wheat and barley were up, and corn also did well.
“Crops like corn really thrive under those conditions; they actually like the heat,” he said.
Stephen Jones, director of WSU’s Bread Lab, said in an email he observed smaller grain yields this year and that temperatures over 85 degrees tend to harm wheat, a cool-season grass.
He reiterated that impacts varied across farms and even within fields, depending on soil moisture.
The Bread Lab is studying how the heat will affect the quality of grains in products such as bread.
“Gluten takes on different forms depending on the heat and dry, and that can of course affect the bread or whatever way the wheat is being used,” Jones said in an email.
As for berries, Lisa Wasko DeVetter, an associate professor of small fruit horticulture at WSU, said she estimates the raspberry crop is down about 20% statewide and the blueberry crop down 10%. She did not have Skagit-specific estimates.
“For Skagit, a lot of our production was less affected relative to areas like Everson and Sumas in Whatcom given we have lots of acreage near cooler, coastal areas,” she said in an email. “Quality suffered on sunburned fruit or fruit that got heat damage, but fruit that developed after the heat wave were fine.”