Oranges on tree

Homeowner Citrus in a Greening World

By Brooke Moffis

Many homeowners moving to Florida hope to grow a citrus tree and a palm to enjoy in their new subtropical yard.  Citrus is associated with Florida because it has been grown by both residents and for agriculture for centuries.  According to Florida Ag in the Classroom, Ponce DeLeon brought citrus seeds to St. Augustine in 1579.  By the 1800s citrus grew in St. Augustine and Tampa.  It is now grown statewide, but with the pressure of the disease, citrus greening, this popular crop is challenging to grow.

Purchasing Citrus Plants

If you wish to buy a citrus, like so many Floridians before, there are precautions to take.  Be sure to locate a reputable nursery that displays a tag on each individual tree.  This is not just any plant identification tag, but one that lists the nursery, the nursery’s registration number and the variety and rootstock of that particular citrus.  These tags refer to the source nursery and certify the source nursery contained disease-free plants at the time of inspection.  Do not begin your citrus experience by planting an infested tree.

citrus nursery tag

A citrus nursery tag should come with any new citrus tree. It assures you that the tree was grown in a nursery certified free of disease.

Know that just because a disease-free citrus was selected, does not mean that the tree will not get citrus greening when planted in the landscape.  In fact, the citrus greening disease pressure is high in Central Florida and the chance that a homeowner’s tree will become infected is also high.

Planting Citrus

Plant citrus in an area in a full sun location where the soil is well-drained.  Prior to planting, amend the soil with compost to increase its ability to hold water and nutrients.  Spread compost out over the entire planting area and work it into the top 6 inches of soil. Do not mulch the plants.

Water citrus twice a week during the dry season from March through June with 1 to 2 gallons of water per application.  Once the rainy season is underway, water as needed.

Fertilization should change depending on the tree’s age.  For a young citrus it is recommended to fertilize about every 6 weeks from late winter through early fall with a 6-6-6 or 8-8-8 citrus fertilizer.  As trees get older, the frequency of application should decrease to 3 to 5 times a year between February through October with a 6-6-6, 8-8-8, or 10-10-10 citrus fertilizer.

Fighting Citrus Greening
citrus greening symptoms

The symptoms of citrus greening include mottled leaves as the bacteria clogs up the vascular system.

To increase the chance of short-term success, after planting treat citrus with the soil applied systemic insecticide imidacloprid.  Imidacloprid acts to control the insect pest that spreads the disease, but is not effective on the disease itself.  Contact insecticides such as oils, soaps, and malathion may also be used, but they must come into contact with the insect pest in order to be effective.  Again, no insecticide will cure citrus greening disease.  Instead, target the pest that spreads the disease.  Be sure to follow the label directions when applying all insecticides.  The label is the law.

It is challenging for homeowners to grow citrus in face of citrus greening.  A citrus tree will eventually succumb to the disease as the fruit and tree quality will decline over time.  At this time there is no cure for citrus greening. Keep trees as healthy as possible by following the above recommendations.  For more information visit Citrus Culture in the Home Landscape and Frequently Asked Questions About Huanglongbing (HLB; citrus greening) for Homeowners.

12 Comments on “Homeowner Citrus in a Greening World

  1. There is a new parasitic wasp that can help to control the insect that spreads citrus greening disease. They are too small to hurt people, but do a great job on psyllids. You can apply to get some from the Florida Dept. of Agriculture and Consumer Services to release in your citrus at http://bit.ly/2vfcI5V. This is a great way to help reduce the disease without having to use any pesticides.

  2. Can you plant a new citrus tree in the same location a tree died of citrus greening? If so, how long do you wait to plant?

    • Yes, you can replant in the same place a tree died of citrus greening. The bacteria only survives in living tissue and is only transmitted by the psyllid insect.

  3. Are all Asian Psyllids carrying the bacteria or only those that have feed off infected trees?

  4. When you cut down or remove a greening infected tree, what do you do with the plant material being discarded? Can you simply put this out for plant refuse pick-up or does it have to be handled in a special way?

    • The bacteria in a greening infected tree cannot be transmitted except through the Asian Citrus Psyllid vector, and they only attack new growth. There is no problem with chipping and mulching the tree, it will not spread the disease.

  5. Is there any place it safe to take a few leaves or a branch to have someone look at it and tell you if you have citrus greening disease

    • Greening is not spread by human contact like Citrus Canker. Greening is spread only via the Asian Citrus Psyllid, a small, piercing/sucking insect. It is safe to bring suspected Greening infected leaves to your local Master Gardener Plant Clinic for diagnosis or to send photos to your local extension agent.

  6. Thanks for the info, I am going to replant after greening and was concerned about replanting in the same place

    • Greening bacteria can only be spread by the psyllid insect vector. It does not remain in the soil and cannot reinfect from there. You are safe to replant, but try a more tolerant type like ‘Sugar Belle’, ‘Tango’, or ‘Bingo’ for best results.

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