Deadly Fungus Kills Florida Palms—But Some Species Fight Back

A deadly fungus is threatening palm trees across Florida, causing sudden collapse and death. Researchers at the University of Florida have now identified which species are most at risk—and which may resist the disease.

The fungus, called Thielaviopsis trunk rot, attacks palms through open wounds. These injuries can come from pruning, insect damage, birds, or even nails hammered into the trunk for lights. Once infected, the disease spreads quickly, often killing the tree.

Scientists at UF/IFAS tested nearly 30 palm species to measure their vulnerability. Their new testing method delivers results far faster than older techniques. Early findings show Buccaneer and foxtail palms are highly susceptible. Meanwhile, Everglades, Cabbage, Florida Thatch, Saw Palmetto, Bismarck, and Pygmy Date palms proved resistant.

The team will now expand their research to include Royal, Date, Canary Island Date, Queen, and Christmas palms. Dr. Braham Dhillon and his colleagues predict Canary Island Date palms will be among the most vulnerable. Syagrus romanzoffiana and Butia capitata, however, may show moderate resistance based on field observations.

The study provides clearer guidance for growers and landscapers on which palms to plant in high-risk areas. By avoiding the most susceptible species, they can reduce losses from this aggressive fungal disease. Further research will refine recommendations for managing the threat.