An incurable citrus tree disease known as Huanglongbing (HLB) has killed hundreds of residential citrus trees throughout Southern California this spring. HLB is caused by a tiny insect no bigger than a grain of rice known as the Asian citrus psyllid. This insect feeds on citrus leaves and stems, which can infect the citrus trees with a bacteria that causes HLB. Huanglongbing affects all citrus plants, including orange, lemon, lime, mandarin, pomelo, kumquat, grapefruit and tangerine trees. It also affects some relatives of citrus, like orange jasmine and curry leaves.
If you’re considering planting a citrus tree on your property this spring, first be sure to get a plant from a licensed nursery in your area. Additionally, you will need to plan ahead to manage pests and diseases on your tree throughout its lifetime.
To grow a healthy citrus tree, follow these tips:
- As the weather warms, 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. Ask your local nursery or garden center about which fertilizer is best.
- Inspect trees for the Asian citrus psyllid and HLB, monthly or whenever watering, spraying or pruning trees. Pest and disease management is critical to protect not just your own tree, but also your neighbors’ trees. Visit CaliforniaCitrusThreat.org to know what to look for.
If you spot the Asian citrus psyllid or see symptoms of HLB in your citrus tree, call the state’s pest hotline at (800) 491-1899. For more tips, visit CaliforniaCitrusThreat.org.