How to Keep a Palm From Growing Tall
Palm trees are available in a variety of sizes, ranging from under 3 feet to more than 200 feet tall, depending on the species. If you cut back a palm's roots or overtrim its fronds, you risk damaging the tree so severely that eventually will die from the trauma.
The easiest way to limit a palm tree's growth is selecting the right species for your needs.
Choose a dwarf palm that will grow to your desired height so that you do not have to risk the tree's health to stop its growth. If you want a tree that grows about 5 feet tall, consider the Licuala palm or the dwarf palmetto, which both grow less than a foot a year. The parlour palm is reputed to be the smallest species of palm and can be as short as 2 feet tall. Check with your local nursery about the many other varieties of small palms.
Cut back the palm fronds in a style known as "hurricane cutting." Lop off the dried brown fronds as well as most of the healthy green fronds, leaving a minimal amount of greenery on top of the tree. Excessively pruning your palm tree this way will stunt its growth, but it also will leave it vulnerable to diseases. Severe pruning will weaken the trunk. Even though it's known as hurricane cutting, this method will make your tree too weak to withstand high winds.
Wait until spring, then use a wooden stick to pull the dry soil off the root system of your ponytail palm. Prune the roots, removing any large pieces and leaving smaller tendrils intact. Cover the roots back up and let them adjust for seven days before watering. This will stunt the palm's growth for about 30 days, but the tree will recover and begin to grow again.