More green for your greens: The bug behind the jump in lettuce prices

a lettuce field
(Via Pixabay)

The cost of lettuce is up nearly 20% since this time last year, with a plant pathogen called impatiens necrotic spot virus to blame. INSV is hitting neighboring Monterey County hard, with some farmers losing the vast majority of their lettuce crop.

This story was originally featured in this week’s Lily Belli on Food newsletter. Be first the first to hear about food and drink news in Santa Cruz County — sign up for Lily’s email newsletter here and text alerts here.

You’re not imagining it — your salad really is getting more expensive. Lettuce prices jumped a whopping 8.9% from October to November and are up almost 20% from this time last year, according to the November report from the U.S. Bureau of Labor Statistics. Although grocery prices rose overall 0.5% last month, inflation isn’t entirely to blame for the price hike.

The cause hits close to home in the lettuce fields of the Salinas Valley in neighboring Monterey County. Known as the “salad bowl of the world,” the area produces 61% of leaf lettuce and 56% of head lettuce nationally, accounting for $1.2 billion in annual lettuce production. Last fall, much of the crop was affected by impatiens necrotic spot virus (INSV), a plant pathogen carried by tiny, millimeter-long insects called thrips. The disease causes necrotic issues, stunting, yellowing and plant death, so infected plants are not harvestable. The insects reproduce rapidly, travel long distances in the wind and can spread the virus among lettuce plants “within minutes,” according to the California Farm Bureau. There is no known treatment for the virus, and sprays for thrips have so far had limited success. The results have been devastating — some farmers in the Salinas Valley are reporting a loss of more than 80% of their crop.

Scarcity drove lettuce prices up, up, up, and the impact is being felt across the U.S. A produce supplier told NPR that a wholesale box of romaine lettuce from California that typically sells for $25 to $30 on the East Coast is costing up to $100. Relief is in sight for consumers, though; as lettuce from Arizona becomes available this winter, prices are expected to drop. INSV was detected in the Yuma growing region in Arizona for the first time in March 2021, although it did not have a significant impact. It’s not yet known how the disease might affect the region in the future.

That offers little comfort to Monterey County farmers, who have struggled with an increasing number of fall infections of INSV over the past three to four years. The agricultural community and researchers are looking for possible solutions, including weeding surrounding areas to decrease thrip habitat, planting lettuce earlier in the year when INSV is less of an issue and breeding lettuce that is resistant to INSV.