A single infected backyard citrus tree in the Murrieta area has triggered a new state quarantine that restricts how residents and businesses move citrus plants and fruit.
The California Department of Food and Agriculture (CDFA) expanded its citrus greening disease quarantine boundary to include the Murrieta area of Riverside County and parts of San Diego County, effective Friday, Sept. 11, according to a CDFA notice published in California Fruit and Vegetable Magazine. The expansion covers three new grid zones: 484, 499 and 510.
The disease, known as huanglongbing or HLB, has no cure.
Infected trees die.
What the quarantine means
Anyone within a five-mile radius of the quarantine zone is now prohibited from moving citrus trees, host plants or plant parts out of the area, according to the San Diego County Citrus Quarantine Program. Fruit grown inside the zone must go through mitigation steps before it can be transported. Commercially cleaned and packed citrus fruit can still be moved under certain provisions.
The restrictions also apply to related plants in the citrus family, including orange jasmine and curry leaf plants, according to CaliforniaCitrusThreat.org, a state-run information site. Regulated movement conditions fall under state regulations (Title 3 of the California Code of Regulations, sections 3435 and 3439).
The quarantine was triggered after CDFA confirmed HLB in one residential tree in the Murrieta area. When a tree tests positive, CDFA removes it free of charge and surveys a 250-meter area around the site. A mandatory five-mile quarantine radius is then drawn from the detection point.
The new zone extends south through De Luz, connecting the northern San Diego County quarantine area with existing quarantines in Orange, Riverside, Los Angeles and San Bernardino counties.
Stakes for local growers
Nursery stock was Riverside County's leading agricultural commodity in 2024, valued at more than $458 million, according to the Riverside County Agricultural Commissioner's Office. The county's total agricultural output that year reached $1.76 billion. Nurseries inside the new quarantine zone cannot ship citrus or host plants out of the area without meeting state mitigation requirements.
CDFA also expanded the Asian Citrus Psyllid Bulk Citrus Regional Quarantine Zone 6 in the same areas, effective Friday, Sept. 11, to match the new HLB boundary.
How to appeal
Any interested party or local entity may appeal the quarantine boundary. Appeals must be submitted in writing, supported by clear and convincing evidence, and filed within 10 working days of the notification. Residents and business owners should confirm the exact deadline with CDFA, since the quarantine took effect Friday, Sept. 11, and the formal notice was published Sept. 14. The quarantine remains in effect during any pending appeal.
Appeals go to: CDFA Citrus Division, 1220 N Street, Sacramento, CA 95814.
Questions about the regulations or quarantine map can be directed to CDFA's Raymond Niem at 916-274-6300 or [email protected]. Residents who suspect HLB or the Asian citrus psyllid, the tiny insect that spreads the disease, can call the CDFA pest hotline at 1-800-491-1899.
Statewide, more than 10,000 trees have tested positive for HLB and been removed since 2012. The CDFA quarantine map, updated Friday, Sept. 11, lists the three new Murrieta-area grids.
