Q. I have lost two mature palms to what I suspect is ganoderma. I would also like to know if there is any way to avoid the spread to my other palms!
A.N., Cooper City
Ganoderma butt rot (basal stem rot) is a fungal disease that is ever present in the environment. The scientific name is Ganoderma zonatum and it kills only palms. In about half of infected palms, a shelf mushroom (conk) will emerge from the bottom portion of the trunk when the disease is advanced.
All palms are considered hosts of this fungus. Symptoms may include wilting (mild to severe) or a general decline in health. A palm cannot be diagnosed with Ganoderma butt rot until the conk forms on the trunk, or the internal rotting of the base of the trunk is observed after the palm is cut down.
Many fungicides have been tried but none are effective against this disease. The only control that can be done is complete removal of the diseased palm as soon as possible, while removing as many of the roots along with the contaminated soil as you can. Palms cannot be planted in the same area again but you can plant other plants and broad-leaf trees instead.
Although removing the conk won’t stop or slow down the disease, it lessens the amount of spores released into the environment. Just twist off the conk and place it in the trash, not in your compost pile. The earlier the conk is removed (when it still is white), the less likely that spores will be released. If you have never seen Ganoderma butt rot on the property, check your palms every six months. Once you have observed the conks on palms or have a palm cut down or die for any reason, monitor your palms at least once a month. Also, monitor the neighborhood, not just your yard. These spores blow with the wind, so it should be a community effort to reduce the spread of this lethal fungus.
To learn more about this palm disease, here’s a link to a UF/IFAS fact sheet: http://edis.ifas.ufl.edu/PP100.