By ROBIN ROBINSON The Key West Garden Club
Think of the fishtail palm caryota mitis as a Southern belle dressed in lots of ruffles, but she is off limits. Don't touch caryota. It contains oxylates which will cause burning and itching, so wear gloves. The unusual spiral anatomy of the fronds of a fishtail palm, makes it easy to identify. Leaflets are triangular and bipinnate. Side branches with leaflets come off of the main branch, creating layers of doubly compound ruffles with jagged edges. The fan-shaped leaves resemble a fishtail. This is the only palm with leaves that are subdivided twice. Eight-foot fronds start out light green and turn dark green as they age.
The wood of this palm is so hard it will defeat a chainsaw, so don't attempt to cut it down. If it is cut down, it will sprout again, so it needs to be dug up and hauled away.
The fishtail palm is monocarpic; once the palm flowers and seeds, it slowly dies over a period of about two years. New shoots come up from the base, like a clumping areca palm or a banana.
The magnificent seeds of the fishtail can be seen on the tiny alley named after General Wiley S. Thompson. When the first American maps of Florida were made in the 1820s, this island was named Thompson Island. General Thompson was truly a wily Indian agent devising questionable practices of deceit and trickery to convince the Seminoles to move west. A Seminole group led by Osceola ambushed and killed him.
The oval, green fruits are 3/4-inch in diameter and turn red as they mature. The five-foot-long mop of seeds is a wonder to behold. The fruit contains calcium oxide and is not edible. Although they take six to eight months to germinate, the seeds propagate readily and many seedlings are found around the palm.
The plant has a lifespan of 20 to 25 years but it may not flower until it is more than 15 years old. The pale yellow flowers are bisexual with one female between two males. They form in mop-like clusters starting at the top of the trunk with subsequent clusters emerging below.
When flowers cascade to the ground, the sound has been described as musical.
This native of Southeast Asia will grow at a moderate rate to about 20 feet in height. It likes well-drained soil, but lots of water. If it dries out, it may start shedding leaves.
A fishtail palm enjoys high humidity and bright sun. It has a low tolerance to salt. If its roots get too wet, it is susceptible to mealy bugs, scale and white fly.
If planted in multiples, space them six feet apart and at least six feet away from the house. If the fronds yellow, add Epsom salts, which contain magnesium. Fertilize two times a year with Palm Special. Because the palm steals nutrition from its fading leaves, do not cut them off.
Fishtail palms have shallow roots and may blow over in a wind. They do not like a freeze. Because they are moderate growers they grow well in a pot.
Green Dean from Eat the Weeds.com said that juice from the flowers make a golden syrup. While the fruit is not edible, the seed kernel is tasty and is used in jewelry making. The tip of the palm leaf is edible, but bitter, as is the palm heart. The sap can be fermented. It does not attract wildlife.
The leaves are animal fodder and the trunk's sheathing can be used as strong fiber for rope. The wood makes sturdy spears. The hollowed-out palm trunk can be used as a gutter to move water.
The University of Florida, IFAS, contends that fistail palm is close to being declared invasive.
Key West Master Gardener Robin Robinson was a columnist for the Chicago Daily News and syndicated with Princeton Features. Her books, "Plants of Paradise" and award-winning "Roots Rocks and Rain: Native Trees of the Florida Keys," can be found at the garden club and on Amazon.com. This column is part of a series developed by the Key West Garden Club. For information, go to www.keywestgardenclub.com.