Citrus trees in Orange County are experiencing a crisis. A treasured part of California’s vibrant citrus heritage and a large contributor to our state’s overall economy, citrus trees in the region are being threatened by Huanglongbing (HLB), also known as citrus greening disease. But by working together, we can stop this deadly plant disease.
The number of HLB detections in Orange County is booming. So far, more than 330 total trees have been confirmed to be infected by HLB, making Orange County the highest concentration of cases thus far in California. By comparison, over 230 trees have been confirmed in Los Angeles County, the historical hotbed for reported HLB cases. Since the first detection in Los Angeles County in 2014, over 500 trees total have been confirmed positive for HLB.
Residents of Anaheim and Garden Grove are seeing a spike in detections, with HLB also spreading to neighboring cities in Fullerton, La Habra, Santa Ana and Westminster. To protect its spread, a quarantine is currently issued throughout Los Angeles and Orange counties. It’s important to remember that it is illegal to bring citrus fruit or plant material into California from other states or countries, and to move it out of quarantine areas.
The deadly citrus disease is spread by a tiny insect called the Asian citrus psyllid (ACP) as it feeds on citrus tree leaves. Now is an important time for California homeowners — 60 percent of whom own citrus trees — to protect their backyard trees by searching for signs of the pest and the disease. While HLB is not harmful to humans, there is no cure; once a citrus tree is infected it will die. Diseased trees need to be removed in order to protect other citrus trees on the property, neighbors’ trees and the community.
While we are seeing a jump of detections in Orange County, all California residents are encouraged to inspect trees for HLB and ACP whenever watering, spraying, pruning or tending to trees. The pest is one-eighth of an inch long and feeds at a 45-degree angle, making the insect appear thorn-like on leaves and stems. Symptoms of HLB include blotchy, yellow leaves; deformed fruit that doesn’t ripen; and excessive fruit drop.
If you spot the disease, call the free California Department of Food and Agriculture Pest Hotline: 800-491-1899.
Taking proper care of your citrus trees will help grow and protect them from harmful pests and diseases. Pest and disease management is crucial to protect not only your own tree but also your neighbors’ trees and the state’s citrus production.
Citrus tree care tips:
• During the first year, apply water at the tree’s trunk. As the tree grows, water a larger area around the tree. Newly planted trees should be watered every three to seven days, and older trees can be watered every week or two.
• Apply fertilizer, including nitrogen, phosphorus and potassium, to soil throughout the year. Zinc or iron deficiencies can result in yellowing leaves, so monitor and apply a foliar spray of zinc or iron if needed.
• Most citrus varieties do not require significant pruning. Lemons are the exception to the rule. Heavy pruning should not take place in winter as it will make trees susceptible to frost damage.
• As part of your tree care, visit your local nursery or garden center to get advice on products that can help protect your citrus tree.
• Be sure to dry out citrus clippings and double bag them before removing the plant material from the property.
• Do not move citrus plants, foliage or fruit into or out of your area, or across state or international borders. This could unknowingly contribute to the spread of the pest and disease.
By working together and acting now, we can preserve our rich citrus industry, enjoy our fragrant and colorful fruit and prevent the expansion of HLB right in our backyards. For more information, visit californiacitrusthreat.org.
Jeff Croy is Orange County agricultural commissioner and sealer of weights & measures.
