(News article for May 8, 2020)
Fall, winter, and early spring are recommended times for planting most trees and shrubs, but palms are different. Because warm soils are favorable for palm root growth, between May and September is the recommended time for planting palms.
There are several things to consider when deciding what type of palm to plant. Maybe the most obvious consideration is whether or not the palm is cold hardy enough for this area. The 2017 - 2018 winter was a good test of what palm species are sufficiently cold tolerant. It showed that we can’t count on growing species like queen palm in the long term.
Another consideration is our soil conditions. The petticoat palm (Washingtonia filiera), for example, is native to dry areas of California and Mexico. I would be hesitant to plant something like this in areas that, like some parts of Tangipahoa Parish, have a water table close to the surface.
Besides tolerance of temperatures and soil conditions, disease resistance of palms is important. Within the past several years, a couple of palm-killing diseases have been found in Louisiana for the first time. Lethal bronzing (also known as Texas Phoenix palm decline or date palm lethal decline) has killed a number of Canary Island palms in the New Orleans area. Chinese windmill palm is common in this area and relatively cold tolerant, but lethal bronzing and a similar disease, lethal yellowing, have been found in dying Chinese windmill palms in the Baton Rouge area. Other palm species affected by these diseases include the edible date palm and the silver date palm (sometimes called the Sylvester palm).
Considering these things, one palm that I think is among the better choices for our area is the cabbage palm (Sabal palmetto). This palm is native to the southeastern United States and is relatively tolerant of a wide range of soil conditions. It’s cold hardy to at least USDA Hardiness Zone 8b, so should be fine, temperature-wise, for all of Tangipahoa and Washington Parishes. While cabbage palm can get lethal bronzing, it doesn’t seem to be as severely affected as some other palms are.
You might notice that I haven’t mentioned the sago palm. This “palm” isn’t actually a member of the palm family but is what’s known as a cycad. While sago palms sometimes experience cold injury, most re-grow. They will likely come back from the roots after a cold winter, even if the top part is killed.
Let me know if you have questions.
Contact Mary Helen Ferguson.
Cabbage palm (Sabal palmetto) on the LSU campus in Baton Rouge, June 2017. (Photo by Mary Helen Ferguson, LSU AgCenter)
The LSU AgCenter and the LSU College of Agriculture