"Could you call it bonsai?" might be the only question raised about this palm growing technique. While the palm’s growth and form cannot be manipulated to the extent of traditional bonsai, the essence of the older plant or larger scene can be suggested in miniature form and this, says one expert, makes it bonsai. Depending on the species, palms can be grown as solitary specimens or groups of one species in a container to suggest mature trees or a whole forest. The unique features of each palm are enhanced in this small scale setting.

South Florida architect and palm tree enthusiast Ken Treister grows an extensive collection of palms in bonsai containers, and it is a viable practice, judging by the health and age of his palms. Treister’s most dramatic creation is six 70 cm (27 inches) tall Hyophorbe verschaffeltii in a rectangular, blue-glazed pot, where their strong forms and red leaf stems are beautifully displayed. A 1.5 m (4.5 ft) tall Chamaedorea metallica looms over its small container home of four years making a daring new statement as well. While some might consider this an odd or inappropriate treatment of palms, it does make for a new way to admire them. Treister has made bonsai palms a hobby for 20 years and has more than one hundred containers arranged along shelves on a patio. Ken points out that he enjoys a large collection of palms in a rather small area and here is an outlet for frustrated palm lovers in apartments.

With close attention to watering and regular liquid fertilizing, palms can be grown for years in bonsai containers. Pure long-fiber sphagnum moss is the recommended potting medium since frequent watering flushes soil media out of these containers. Seedlings or small plants cleaned of all soil are carefully arranged in the container with sphagnum moss packed in around them. Moss and even miniature mondo grass can be placed over the sphagnum moss as a groundcover . Due to the rootbound state of the palms, watering is a nearly daily ritual, and fertilizing typically consists of a weekly liquid 20-20-20 drench. Treister rootprunes as often as twice a year to keep the plants within their containers, and this involves cutting large emerging roots of single specimens or sawing a bottom portion off multiple plant roots, and then repotting with sphagnum moss around the cut areas.

Palms cannot match the longevity of traditional bonsai, but many species remain an appropriate size in bonsai containers for 5–10 years. Faster growing palms such as Roystonea sp. have been retired as early as four years when they reached 1 m (3 ft) in height. Some of the best subjects for bonsai include species of Arenga, Rhapis, Livistona, Hyophorbe, Chamaedorea, and Dypsis . Some named varieties of Rhapis excelsa, such as R. excelsa ‘Kodaruma’ can stay in the same pot for decades, only reaching 1 m (3 ft) in height.

sources: myself, Ed Green, Ken Treister, and Copyright © 2001 The International Palm Society.