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.
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.
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
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.