Brown Spots on Fig Leaf & Ficus

Distinction

• Fig plants total more than 800 species worldwide in the genus Ficus. In the U.S., they grow in U.S. Department of Agriculture plant hardiness zones 6 through 12. Upright forms include weeping fig (Ficus benjamina), fiddle-leaf fig (Ficus lyrata) and rubber tree (Ficus elastica), all of which grow in USDA zones 10 through 12. Creeping fig (Ficus pumila) is a vine that grows in USDA zones 9 through 11. The common fig (Ficus carica), which grows in USDA zones 6 through 9, is the species that bears edible fruit. In some regions where the common fig has escaped cultivation, it poses an invasive threat. Regardless of species, all fig plants are susceptible to the same leaf-spotting diseases.

Fungal Diseases

• Numerous fungal diseases may infect fig plants. Wet environments encourage the growth of fungal spores, which is how the causal pathogens are able to reproduce and spread. Fig anthracnose may be caused by various fungi, primarily Colletotrichum and Glomerella species. Anthracnose and Cercospora species fungi commonly infect fig plants during the warmer wet weather of summer. Gray mold, which is also called botrytis blight because of the Botrytis cinerea causal pathogen, is more common on fig plants during cooler spring weather, especially during rainy periods.

Bacterial Blight

• Xanthomonas leaf spot, also called bacterial blight, is the most damaging bacterial disease of fig plants, reports the University of Florida IFAS Extension. Caused by the bacterial pathogen Xanthomonas campestris pv. fici, this disease enters a plant through openings created by wounds, or through the stomata, which are natural breathing pores located on the leaf surfaces. Once bacterial blight has penetrated a plant, it spreads systemically, sometimes quickly, and may kill the plant.

Management

• Leaf spot diseases are difficult to control once you see these symptoms on fig leaves. After the brown spots appear, a disease has already taken hold, and fungicides or bactericides cannot cure the disease. If you break the life cycle of pathogens, you may be able to slow the effects and stop the spread of a disease. Fungal disease can only reproduce in water, so keeping fig leaves as dry as possible is a primary objective in disease management. Don’t water from above by using water wands or sprinklers that wet the leaves. Always remove dropped leaves underneath plants because they harbor fungi and bacteria that continue to live and re-infect plants.