Rodent Pressure Grows in California Almond Orchards

The Almond Board of California reports that almond orchards in the Southern and Western San Joaquin Valley are facing a major roof rat outbreak. More than 100,000 acres have been affected, with some growers estimating up to 50% crop loss—even while trapping dozens of rats daily.

These rodents are causing more than just crop damage. They’re chewing through irrigation lines, equipment wiring, and even starting fires. Total losses could range from $109 million to over $300 million, with irrigation repairs and lost yield making up the bulk of that impact.

Roof rats, once mostly in the trees, are now burrowing and using irrigation canals to spread across orchards. Researchers recommend using tracking tools, elevated bait stations, and trapping as part of a tailored pest management approach—but growers say the labor and costs are overwhelming.

Industry groups are stepping in to help, with more resources and updates expected at this fall’s pest control advisor meeting and at The Almond Conference in December.

For the latest, visit https://www.almonds.com/