“This is the most significant plant disease invasion into California in modern history”


Fruit on the Parent Navel Orange Tree that started the California citrus industry

California’s citrus industry accounts for $2 billion in revenue. You would think a disease that threatens the industry would get more attention, yet this is the first I have heard about it. According to Yahoo news, “state bug detectives fanned across…suburban Los Angeles neighborhood Monday, vacuuming backyard trees with bug catchers, setting traps and taking tissue samples from citrus in a frantic effort to stop the spread of a deadly disease detected there last week.”

According to the article, “the USDA confirmed on Friday what state agriculture officials had feared: Both a psyllid and the 8-foot, 8-year-old grafted lemon-pummelo tree where it was found March 22 in the Hacienda Heights suburb of Los Angeles County were infected with huanglongbing. The disease is ‘citrus greening’ which is transmitted by ‘an infected psyllid.’  A psyllid is an insect that when feeding on a citrus leaf can transmit the disease from one tree to another. ‘This is the most significant plant disease invasion into California in modern history,’ said Ted Batkin of the Citrus Research Board.”

Are you an organic gardener? State inspectors are fanning out across LA searching for the bug, and potentially infected tree’s. If you have a infected tree the state will, “spray the tree with the pesticide TEMPO, a pyrethroid-type insecticide that lasts up to 30 days.” Then they will remove the tree for destruction. “The state is asking the Office of Administrative Law for emergency authority ordering mandatory treatment all of the trees in the half-mile zone in an attempt to kill the psyllids and prevent the spread of the disease. County agriculture officials are working to educate homeowners by mailing out information prior to a community-wide meeting April 9″.

I remember the early 80’s living in The Bay Area, helicopters would fly over at night spraying Malathion in an attempt to eradicate The Mediterranean Fruit Fly. Ironically, the man who ordered the spraying then was Governor Jerry Brown, our current governor. Of course aerial spraying would be much more difficult to pull off in today’s environment. So for now state inspectors are walking door to door hanging traps and inspecting trees. “In one 15-minute span on Monday CDFA trappers using vacuum-like devices collected 25 Asian citrus psyllids from a single backyard tree in the target area.”


State historic site #20

I think this would be a great opportunity for garden centers, nurseries, and garden bloggers.  Use the power of social media to inform, and help people understand the nature of this threat. With so much happening in the world stuff like this can “end up under the fold” so to speak.  As the Yahoo article say’s, “the people of Los Angeles County need to realize how important this is. It’s so common to have citrus in residential backyards, and nobody wants to see widespread losses there.”

Here is a post I did awhile back on the original Washington Navel Orange Tree, which still lives in the middle of a busy thoroughfare in Riverside. That tree has sure seen a lot of changes in the 130 plus years of it’s existence.

About Trey Pitsenberger

Trey is a nurseryman, author, and speaker.

03. April 2012 by Trey Pitsenberger
Categories: | Tags: , , , , , | 8 comments

Comments (8)

  1. Pushed out an alert on GardenQuest Timeline. ~ Steve

  2. Thanks Steve,
    How fascinating that one day important news and information might be spread via “games” and “gamers”.

  3. Very scary stuff — we have seen the psyllid in our area in TX but not the disease. But it is responsible for the citrus quarantines you read about. The most important thing? Don’t move citrus into or out of quarantined areas.

  4. Trey, it is estimated of homes ( in California) that are 20 years or older, that 60% of them have some variety of citrus planted in the landscape.

    This huanglongbing ( Citrus Greening ) could devistate our industry like it is the Florida industry right now.

    Here is info from UC Davis:


  5. Thanks for the info. I am passing it along also.

  6. Hello Trey:

    Wonderful article on an extremely devastating out – break in the world of citrus. Although I am ranching in Southern California, I have family in the SJV who are some of the last truly Independent Naval and Valencia Citrus growers left in that area and you have to believe me when I say they are more then worried and on the watch. The struggle to remain Independent farmers and ranchers in California has not been easy for decades and something like this can truly put an end to a way of life.

    As an Independent rancher and family as Independent Citrus growers we don not fly under a flag of corporate Insurance with guaranties! If cattle prices fall or our crops fail we absorb the hit! We don’t have insurance to cover the loss… We are left to sell land, acquire out side employment whatever it takes to remain Independent (it’s a way of life).

    However this “huanglongbing” has the ability to wipe out the California Citrus Industry all together.

    I thank you for writing this article and I will share it.

    Thank you,

    Annie Haven

    • Annie,

      Thank you for your heartfelt response. One of the responsibilities we as garden writers have is spreading the word to people who might not have gotten the word in the past. Social media allows us to reach people who can continue to spread the word. With the intense interest in “growing your own” these day’s, citrus can play a big role where possible. With the inevitable cut’s in government monitoring of issues like this, it will fall to us to create a garden bloggers “early warning system”. I think in the future a system such as his will actually be more effective than what we see at work now. Use the power of social media and peoples vested interest to make a difference.

      • Yes, Trey I agree and again I am so glad you wrote this article to bring awareness to the home gardener, who I consider the “New Farmer”. Issues like this affect growers as well as farmers and home gardeners. With quarantines in place no Orange Citrus will be sold in the affected areas for two years. It’s the trickle down affect with long term repercussions that is so hard on the industry as a whole. I will continue to share your article to help bring further awareness. Again Thank you Annie Haven