Why Is My Orange Tree Dying?

A woman enjoys the bounty of the orange tree.

Much to the chagrin of farmers and gardeners, pests, disease, weather and age can all play a part in determining the mortality of an orange tree for both commercial and home growers.

Blight

Young, immature orange trees are particularly susceptible to early death. The Purdue University Horticulture Department reports that blight, also called young tree decline, leads the way in the number of orange trees lost each year in Florida -- nearly 500,000 annually. Once thought to be caused by nutritional or soil deficiencies, blight is now considered an infectious disease.

Weather Damage

Orange trees are a subtropical species and not particularly tolerant of cold -- thus the reason they thrive only in warm climates. Orange trees that have been damaged by freezing or a frost may eventually die, with the tree displaying symptoms of damage, such as sour-tasting, water-logged or pithy fruit.

Other Diseases

Orange trees may fall prey to a variety of fungal, viral and bacterial infections that threaten their existence. Citrus Phytophthora gummosis attacks the bark of the tree, while greasy spot is another fungal infection that instead infects orange tree leaves. Citrus tristeza is a viral infection that slowly destroys an orange tree over the course of several years.

References

• Purdue University Horticulture: Orange
• University of Arizona Cooperative Extension: Diseases of Citrus in Arizona