How to Protect Your Lemon from Deadly HLB disease

The Citrus psyllid insect that can transmit the deadly HLB Citrus Disease has been found in San Mateo County, continuing its march up the State from Southern California.  San Mateo County and 1/3 of southern San Francisco are in Quarantine! Click here to find out what the quarantine means and how you can protect your lovely lemon tree.

The Asian citrus psyllid is a small insect that feeds on the leaves and stems of citrus trees. The insect is extremely dangerous because it can transmit a disease that is fatal for citrus. The deadly bacterial disease is called Huanglongbing (HLB), also known as citrus greening disease, and it has been found in Southern California, putting all citrus trees at risk. Once a tree is infected with HLB, there is no cure and the tree will die. So far, only the psyllid insect has been found in the Bay Area, NOT the disease!  The best way to prevent the disease from reaching our garden trees and killing them is to stop the Asian citrus psyllid.  YOU ARE CRITICAL IN THIS FIGHT!

How to stop the spread of Citrus Psyllid

The Asian citrus psyllid can fly short distances and be carried by the wind. However, a main way the Asian citrus psyllid spreads throughout the state is by people transporting infested plants or plant material.  Here’s what you can do:

  • If you are planting a new citrus tree, purchase only from a reputable nursery that will certify the stock (look for a tag or ask). 
  • If you like to share your lemons or citrus fruit, please wash them first and make sure that there are no stems or leaves/branches attached. It may look ‘clean’ but please do not take a chance.
  • Grafting: Please do not graft citrus anywhere! You may inadvertently be the cause of killing the Bay Area’s citrus crops, even your own!

What if I am in the quarantine area?

Check the maps here to see if you are in the Quarantine Area.  If so, here’s what it means:

1)  You may still plant a certified Lemon or other citrus tree

2)  You may still share your lemons (or others you glean) if they are washed and have no stems, leaves or branches with them

3)  You are not allowed to graft any citrus onto any other trees anywhere in San Francisco.

Please check out our website for periodic updates about the citrus psyllid status in San Francisco.