Hot, then cold temps stress lettuce crop

Winter lettuce grown in the desert Southwest is going to be in short supply for a while and cost more as a result of a “perfect storm” of unseasonably warm weather last fall and the more recent cold weather and freezing temperatures of the past few days.

Yuma County provides much of the nation's leafy greens from November to March, and farmers are reporting damage to many lettuce crops, in particular romaine and iceberg.

Some areas are being hit harder than others because of Yuma County's microclimates, said Kurt Nolte, executive director of Yuma County Cooperative Extension. Yuma Valley stayed a little warmer ,but overnight temperatures have dipped into the mid-20s in the outlying areas of the eastern part of the county, he explained.

The impact of the colder weather on lettuce is three-fold, Nolte said. It slows the growth of the lettuce, delaying its readiness for harvest and throwing off the production schedule. More immediately, it causes ice to form in the lettuce heads, ice that has to melt before the crop can be harvested, thus disrupting the workday. And the freeze is damaging the outer leaves, so crews are having to take more time to trim off those outer layers of leafy material.

“So we will see a big spike in prices,” Nolte said.

The price for lettuce in Yuma is now around $24 for a carton of 24 heads. Before Christmas, cartons were going for $7 to $8 because of an oversupply brought about by the warmer-than-usual October and November, he said.

“The lettuce that was scheduled to be harvested today was cut in December because it was ahead of schedule,” Nolte said. “More lettuce was planted in December to fill the gap in production, but with the cold weather it's not growing fast enough to make up for it.”

And so, he said, he expects lettuce will be in short supply for the next three or four weeks.

“It's squeezing the whole industry. Orders all over North America are waiting to be filled.”

However, Nolte is hopeful the production will be back on schedule by mid-February.

With 80,000 acres of lettuce in the Yuma area, it's virtually impossible for growers to protect their crops, he said. That's too much acreage to cover, and wind machines wouldn't be practical because lettuce fields rotate.

Nolte said hardest hit by the freeze are romaine and iceberg heads within three weeks of harvest. Leafy crops such spinach appear to be less impacted, and the cole crops — broccoli, cauliflower and cabbage — are less sensitive to the cold.