Ganoderma butt rot, caused by the fungus Ganoderma zonatum, is one of the most common fatal diseases affecting palms in Florida. It affects every palm species grown in the state and there is currently no cure.
What to look for
The clearest sign is a hard, shelf-like conk growing directly on the lower four to five feet of the trunk. The conk usually appears white on top when new and turns brown and woody with age. Other symptoms can include wilting, slower growth, and frond decline that starts from the bottom of the canopy and works upward. Unlike some trunk diseases, the wood itself does not become soft to the touch, which can make the problem easy to miss until the conk appears.
Why it is so serious
The fungus degrades the internal structure of the lower trunk from the inside out. By the time a conk is visible, significant internal decay has usually already occurred, affecting the structural stability of the palm. Because there is no treatment once the disease is established, prompt removal is typically recommended to reduce the risk of a sudden trunk failure.
Why removal alone is not the end of the story
Ganoderma zonatum survives in the soil at the site of an infected tree, sometimes for years. Replanting another palm in the exact same location carries a real risk of the new palm eventually becoming infected as well. Property owners considering replacement should factor this into their planting plans.
What to do
If you notice a shelf-like growth on a palm trunk, have it evaluated as soon as possible. ArborManagers provides palm and tree health assessments throughout Central Florida and can help you understand your options. Call us at (352) 414-2454 or request a consultation online.