Something is wiping out Florida’s palm trees. Here’s what to watch for

Florida’s palm trees are being increasingly jeopardized thanks to a disease that’s spreading through the state.

That’s according to UF/IFAS’ Larry Figart, an extension agent in urban forestry for the Duval County Extension Service.

In a blog post earlier this year, Figart touched on the threat, identified as “Lethal Bronzing Disease” (LBD).

[BELOW: Florida’s native palm trees are under attack]

Researchers said that the disease was first encountered in Florida back in 2006, when it was discovered in Hillsborough County.

Nowadays, the disease has spread throughout over 30 counties statewide, primarily in Central and South Florida.

“The disease is caused by a bacterium without a cell wall called a phytoplasma that is spread from tree to tree by a treehopper called the palm cixiid,” Figart writes. “The treehoppers feed off the phytoplasma-laden sap of an infected tree and carry it to an uninfected tree, thereby spreading the disease.”

According to state officials, flight activity for these cixiids tends to be relatively low in September, though it ramps up by November and December.

Figart says that palm trees infected with this disease may show an array of symptoms, the earliest of which involve any fruits on the tree dropping all at once.

From there, the central spear leaf emerging from the top of the tree dies, signaling the death of the tree’s “heart.”

Fronds may then turn a reddish-bronze color as they dry out and die, typically starting from the lower fronds upward.

Per Figart, these symptoms usually become noticeable about 4-5 months after the tree becomes infected, and most palm trees die roughly 2-3 months after the first symptom is spotted.

But the biggest problem here is that once a tree has become infested, there’s no way to cure it, Figart adds.

Instead, any tree properly diagnosed with LBD should be immediately removed to mitigate the chance that treehoppers spread the disease to other trees. Nearby palm trees should also be tested to ensure they don’t carry LBD.

This was the case last month after Clearwater’s Coachman Park was forced to remove several of its palm trees after they became infected with LBD.

“The good news (if you want to call it that) is that this disease cannot be spread by pruning tools, as is the case with other palm diseases,” Figart explains.

To prevent infection, palm trees can be treated with doses of the antibiotic OTC, with repeated injections every three months. While effective, this treatment does create wounds in the trunk, which don’t heal in palm trees, Figart says.

Another option that hasn’t been as thoroughly studied is to use a pesticide called “imidacloprid” on the root area of the tree, which is effective in killing planthoppers, Figart continues. This helps owners avoid wounding the trunk, though it comes with another downside, as the pesticide is harmful to bees.

Regardless, owners who suspect their trees may be infected with LBD are encouraged to send a sawdust sample to the University of Florida’s Plant Disease Diagnostic Center for diagnosis.

Figart says that a sample can be obtained by using a battery-powered drill and a sterilized 5/16-inch drill bit, though the sample should be kept refrigerated until it’s sent to the lab.

For more information on how to collect a sample, click here.