For La Cañada homeowners used to enjoying backyard-grown oranges and lemons, news of a citrus disease’s recent appearance in Hacienda Heights is raising an alarm.
The disease, called huanglongbing, or citrus greening, is an incurable bacterial infection that attacks the vascular system of citrus plants, slowly killing them.
One infected tree in Hacienda Heights so far is the only documented case of HLB in California. But because its insect carrier, the Asian citrus psyllid, has been in the state since 2008 and Los Angeles since 2009, California Department of Food and Agriculture authorities are being vigilant about its spread.
“Anyone with a citrus tree in Southern California should be concerned,” said agency spokesman Steve Lyle. “It’s a disease that history has shown will spread.”
The Food and Agriculture Dept. has instituted a two-year quarantine for citrus trees in a 93-square-mile zone centered around Hacienda Heights. Sales of citrus trees are banned in the area, and only commercially cleaned and packed fruit is allowed out — residential citrus must be consumed where it is grown.
Although La Cañada Flintridge is outside the quarantine area, it is subject to a less onerous Asian citrus psyllid quarantine that covers all of Los Angeles, San Diego and Ventura counties. That quarantine prohibits the movement of host nursery stock out of quarantine areas.
Eric Ryan, manager at the Armstrong Garden Center on Foothill Boulevard, said the store is not facing a direct impact from the new quarantine, but added the disease is a threat.
Ryan said his store sells five or six citrus plants a day. While the company’s citrus plants are grown in protected grounds, once they’re shipped out, they become susceptible to the disease.
Agriculture officials are emphasizing awareness of the disease among the countless area residents with citrus trees on their properties.
Ted Batkin, president of the California Citrus Research Board, said homeowners should be keep an eye out for the signs of the disease, which include lopsided fruit and yellow shoots. More information is available at www.californiacitrusthreat.org.
“This is a very strange and difficult disease in that there’s no cure for it,” he said. “The long-range impact is that if we don’t stop this early, it has the potential of making it not possible to grow citrus anywhere in California.”
Batkin said that it’s crucial for infected trees to be identified quickly. While the disease can take three to four years to kill a tree, during that time the infected citrus serves as reservoir for the disease-spreading psyllids.
California has a $1 billion-plus commercial citrus crop, but Lyle said that in the Los Angeles area, the real issue is preserving the backyard orange or lemon tree.
“Fifty to 70 percent of all homes in Southern California have citrus on the property, so it’s a significant cultural influence,” said Lyle. “The real issue is saving the citrus for homeowners.”
Residents who think they have spotted HLB symptoms are asked to call the Department of Food and Agriculture's hotline, (800) 491-1899.