Why Santa Clara County is going door to door looking for Costco purchases

Santa Clara County agricultural officials have launched an unusual door-to-door tactic to track down approximately 1,300 grapevine and desert willow plants sold at Costco locations in California that may be carrying a destructive invasive pest.

The unusually aggressive effort zones in on customers who purchased these plants between April and early July 2026.

Officials are urging residents to check their yards and report any such plants bought from Costco, as they could be harboring the glassy-winged sharpshooter, an insect known to spread Pierce’s disease.

According to county officials, the plants in question were sold at Costco locations in Santa Clara County.

The California Department of Food and Agriculture issued the alert urging anyone who purchased grapevines and desert willows from Costco to contact authorities for inspection and removal, which has allowed Costco to promptly recover about 200 plants thus far.

Santa Clara County is conducting the targeted home visits to locate, physically uproot and safely destroy any potentially infected plants before the pest can spread.

“We really wanted to start here in South County because this is where a big part of our grape and wine industries [are] located, so we want to provide protection for our growers,” Ericka Mora, Santa Clara County deputy agricultural commissioner, told NBC Bay Area.

Pierce’s disease is a deadly bacterial infection that blocks water-conducting systems in grapevines, ultimately drying them out and killing them. The glassy-winged sharpshooter feeds on plant sap and rapidly transmits the disease, which has already caused significant damage to California’s wine-producing regions.

The pest, which has no known cure, has been a major concern for California vineyards as it devastates vineyards in regions like Napa.

The effort to stop this potentially disastrous invasion comes as California continues to battle threats to its multibillion-dollar agriculture sector already strained by bureaucracy and water issues.

Residents who bought grapevines from Costco are urged to contact their local County Agricultural Commissioner’s Office right away.

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