Q: I have been told my citrus tree has citrus greening and there is nothing I can do to save it. Is this true?
A: Citrus greening is a bacterial disease spread by a tiny insect called the Asian citrus psyllid. The bacterial disease damages the vascular system of the plant eventually restricting nutrient and sugar movement. As a result, the infected citrus will decline slowly over time.
There is currently no cure for citrus greening. Applying imidacloprid, a systemic insecticide, to the root system can help keep Asian citrus psyllid populations under control but will not cure the disease once the citrus tree has it.
If you know that your citrus tree already has greening, there are a couple of options. You can destroy the tree by cutting it off at the base and treat the stump with an herbicide in order to prevent sprouting. Since the citrus greening disease is systemic, new sprouts coming from the roots or stump will act as a reservoir of the disease. Before cutting the tree down, treat it with a foliar applied insecticide labeled for citrus to kill any psyllids.
Removed branches, trunks and limbs should be disposed of as you would any landscape debris. The disease is not spread by touching the leaves, stems or fruit. When the leaves wilt once the tree is cut down, the Asian citrus psyllid will no longer feed on the tree as this insect prefers soft, succulent growth.
If you wish to replant with citrus, the bacteria is not spread by contact, so the new plant will not become infected from any remaining dead plant material. Look for a certified nursery tag when selecting your tree. Certified nurseries selling citrus trees are inspected for citrus greening every thirty days. Once you plant a citrus tree in your yard, there is a very good chance that the new tree will become infected too as the citrus greening disease is widespread throughout Central Florida.
You may also choose not to plant citrus and look for alternative fruit crops such as pomegranates, peaches, nectarines, plums and blueberries.
Another option for dealing with a tree infected with citrus greening is to try to keep your citrus as healthy as possible through proper watering and fertilization. Fruit from an infected tree is safe to eat, but there will come a time when the fruit will no longer taste good and the tree will become unproductive. Once this occurs, you should remove the tree.
If your citrus tree has been in decline for some time and you are not sure whether or not you have greening, bring a sample into the Master Gardener Plant Clinic. Our volunteers will be able to tell you if it is symptomatic. You may also visit gardeningsolutions.ifas.ufl.edu and search for citrus greening for further information.
Please visit our Master Gardener Plant Clinic and Discovery Gardens. Both are open from 9 a.m. to 4 p.m. weekdays at the Lake County Extension Office, 1951 Woodlea Road in Tavares.
Brooke Moffis is the Residential Horticulture Agent of the UF/IFAS Lake County Extension office. Email burnb48@ufl.edu.