Three planes, one palm – a Madagascar wonder
By Ralph E. Mitchell
While many palms are more or less tubular and rounded in structure, the triangle palm offers an angular three-sided shape unlike any other palms in our local landscapes. The fronds grow in three distinct growing planes giving the triangle palm a unique appearance which elevates its appeal to both palm collectors and backyard growers alike. Have you seen this exotic palm from Madagascar in a neighborhood near you?
The triangle shape of the triangle palm is formed by three separate rows of fronds stacked on top of each other giving the base of the crownshaft a three-dimensional appearance. The base of these fronds flares out a bit from the crown and is very noticeable. The fronds are bluish-green in color and up to ten feet long with a pinnate or feather-like structure topped with a slight curve at the top most portion. The lower fronds develop long, thread-like leaflets called reins that hang down almost to the ground. Some find the appearance of these fronds a bit shaggy, but overall I think that it gives a graceful look to the triangle palm. The gray trunk is stout and the ultimate height of the palm rarely gets over fifteen feet tall. On mature specimens, up to five-foot long flower spikes appear in the spring covered with tiny light yellow flowers. One-inch long, egg-shaped yellowish fruits can develop. Although it is best planted in the warmer parts of our region as it is listed for USDA hardiness zone 10 to 11, it is also noted as tolerant to lower temperatures once established.
Once established, the slow-growing triangle palm is very tolerant to our Southwest Florida soils. However, some supplemental watering and the addition of a proper palm fertilization program is recommended for best results. In general, we would recommend a granular fertilizer 8-2-12-4 (or 8-0-12-4) applied in November, February and May as per label directions. In August use a 0-0-16-6, again as per label directions. The triangle palm is very susceptible to Potassium deficiency, so keep an eye on this issue.
We have a triangle palm at our East Port Environmental Campus Demonstration Garden on Harbor View road. After many years, it has matured into a fine specimen. Triangle palms are useful in the landscape when planted in buffer strips and as accents. A number of triangle palms are growing successfully in other parts of Charlotte County, and are readily available at most garden centers and nurseries – check it out! For more information on all types of palms suitable for our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.
Quitana, H. V., Andreu, M. G., Freidman, M. H. & McKenzie, M. (2016) Dypsis decaryi, Triangle Palm. The University of Florida Extension Service, IFAS.
Broschat, T. K. & Black, R. J. (2016) Ornamental Palms for South Florida. The University of Florida Extension Service, IFAS.
Bielski, J. (1999) Neodypsis decaryi. Floradata.com. Tallahassee, FL.