It is possible to grow citrus in your home garden
The Wall Street Journal reported recently that orange juice prices are expected to climb after the forecast for the smallest orange crop since 1945. The Florida oranges are smaller than usual and keep dropping out of trees as disease spoils the juice crop.
The disease causing this problem not only in Florida but over the entire world has been referred to by several names over the last hundred years but the official name is Huanglonbing (HGB), which means yellow shoot disease. More commonly, the disease is referred to as citrus greening — a much easier term to remember and pronounce.
The disease is everywhere and will reduce the yield of the crop and if not treated, will kill the citrus tree within five years. The causative agent is a bacterium (Candidatus Liberibacter asiaticus) and is transferred from citrus tree to citrus tree by a small bug referred to as the Asian citrus psyllid (Diaphorina citri Kuwayama). What actually happens is the bacteria clogs up the transporting vessels that carries the sugar from the leaves to other parts of the plant including the fruit and the roots. Therefore the fruit is smaller and often sour and the roots are starved for food.
The symptoms of this disease are a yellowing branch, a notch left on the leaf by psyllid damage, leaf drop, reduced fruit size, bitter sour tasting fruit, poorly colored fruit that is often lopsided, excessive fruit drop and a blotchy mottled effect on the leaves. The last symptom is the best way to diagnose if the citrus tree has citrus greening. There is no symmetry of the light green and dark green patches on either side of the vein.
With all this bad news, it is still possible to grow citrus in the home garden. Special care is needed to maintain a somewhat healthy tree. The treatments include aggressive control of the psyllid (insecticides), soil fertilization, foliar feeding (citrus micronutrients) additional watering during the drier months, pruning deadwood and weak branches, weed and lawn grass control under tree canopy.
This sounds daunting but a regular schedule 3 or 4 times a year can keep a tree happy. As mentioned above the weeds and the lawn grass under the tree canopy should be removed by hand or killed/controlled with herbicide to allow uptake of fertilizer and water by the citrus tree. Mulch can be used but keep it 8-9 inches away from trunk. The tree should be watered two times a week when insufficient rainfall has occurred.
Spraying of the citrus trees should occur three times a year. In February when the new leaves are about 1 inch long, in May before the rains start, and in October after the rains have stopped. The spray recipe is a mixture of insecticide (malathion or neem oil), citrus foliar spray and copper fungicide. All 3 can be found in any big box store or nursery. The amount per gallon of each ingredient should be in accordance with the label instructions. After adding all 3 ingredients to the sprayer, fill the sprayer to the appropriate mark with water.
Apply citrus fertilizer in accordance with the label instruction at about the same time as the spray.
And to make things easy, apply Bayer Advanced Citrus insecticide or other systemic insecticide once a year as a soil drench to prevent the psyllid from attacking again. Follow the recipe on the bottle. Simple mix it in a bucket and pour around tree.
So to review: 1. Remove weeds, 2. Water when dry, 3. Spray 3 times year, 4. Use Citrus fertilizer 3 times/year, 5. Use Bayer once a year.
Here’s hoping your citrus trees will be happy trees.
Kathy Woodlock is Past President Garden Club of Cape Coral, a Master Gardener/Citrus Advisor and flower show judge.
To reach KATHY WOODLOCK, please email news@breezenewspapers.com