California regulates the movement and sourcing of citrus trees to protect commercial and backyard crops. While trees are widely available in retail settings, strict rules mitigate the spread of devastating threats. These threats include the bacterial disease Huanglongbing (HLB) and its vector, the Asian Citrus Psyllid (ACP). Understanding these sourcing and movement restrictions is necessary for any resident adding a citrus tree to their property.
General Availability and Certified Sourcing within California
California residents typically purchase citrus trees at local nurseries, garden centers, and large home improvement stores. The most important factor when buying a tree is ensuring it comes from a registered source that adheres to state agricultural standards. All citrus nursery stock sold within California must be propagated under the Citrus Nursery Stock Pest Cleanliness Program, a mandatory initiative overseen by the California Department of Food and Agriculture (CDFA).
This program ensures that the source material used to grow the trees is tested and verified as free from regulated pests and pathogens, including the bacteria that causes HLB. Look for documentation or tags on the tree that confirm its origin from a licensed nursery participating in this clean stock program. The budwood, or plant material used for grafting, often originates from the University of California, Riverside’s Citrus Clonal Protection Program (CCPP). These measures reduce the risk of a new tree inadvertently introducing a pest or disease into a backyard or commercial orchard.
The Strict Rules for Importing Citrus into California
Bringing citrus trees into California from any other state is almost entirely prohibited for the average consumer, making out-of-state mail-order purchases illegal. California maintains rigorous agricultural exclusion laws to shield its multi-billion dollar agricultural industry from invasive threats. The entire Rutaceae plant family, which includes all citrus varieties, is banned from entry unless complex commercial permits and inspections are secured, a process impractical for home gardeners.
These regulations specifically target pests and diseases not yet widespread in California, such as citrus canker, a highly contagious bacterial disease. State border protection stations are positioned along major entry points to inspect vehicles and confiscate any prohibited plant material, including citrus trees and fruit. Intentional importation of plant material that causes an infestation can result in significant legal consequences, including civil or criminal penalties with fines reaching up to $25,000 per offense. Consequently, residents should only purchase trees that have been propagated and grown within the state’s certified nursery system.
Understanding Local Citrus Disease Quarantine Zones
Even after acquiring a certified tree within California, its movement and planting may be subject to further local restrictions depending on the buyer’s residential location. A quarantine zone is established by the CDFA in areas where the deadly Huanglongbing disease or its vector, the Asian Citrus Psyllid, has been detected. These zones are typically defined by a five-mile radius surrounding a confirmed HLB-infected tree.
The primary restriction for residents within a quarantine area is the absolute prohibition on moving any citrus plant material, including the tree itself, cuttings, and unwashed fruit, out of the zone. This rule prevents the accidental transport of the Asian Citrus Psyllid or the HLB bacteria to clean areas of the state. If a resident lives within an established HLB quarantine zone, any new citrus tree purchased must have been grown in an approved, insect-resistant structure to minimize the risk of the psyllid infestation. Homeowners in these areas also have a responsibility to regularly inspect their existing trees for signs of the disease and report any concerns to the CDFA to help contain the spread.