Although often referred to as trees, palms do not grow in the same manner as an apple, oak or maple tree. Palms do not branch, develop bark, or grow in girth from a layer under the bark called cambium. Palms grow only from a growing tip, sometimes called a crownshaft, on the tip of the trunk or thin stem. Cutting off this growing tip on single-trunked palms effectively kills the plant. On multi-stemmed palms, also called clustering palms, the plant continues to grow but rejuvenates new stems from the roots to replace the removed one.
Around 2,500 different species of palms exist, native to all continents except Antarctica. Both treelike and shrubby palms grow in tropical, subtropical and warm temperature regions. Palms display either feathery fronds or rounded, fanlike fronds and grow as a clustering clump or as solitary trunked plants. Clustering palms produce multiple thin stems, each with a growing tip. Sometimes new growing tips emerge from the roots; these are referred to as suckers. A sucker is a genetic clone of the palm and will rejuvenate into a mature palm if the trunk or other stems die or are cut off.
Clustering palms -- those with multiple stems -- may have some stems pruned back to the ground. Removing them does not kill the palm, but the stem that was removed will not rejuvenate itself. Even if all stems on a clustering palm are cut back to the ground, suckering shoots from the roots will arise and grow, eventually growing tall and creating a palm that looks healthy. Only healthy clustering palms effectively sucker and rejuvenate; those that are sick with disease or stressed and weakened from dry or nutrient-deficient soils will not rejuvenate. Examples of clustering palms include areca palm (Dypsis lutescens), everglades palm (Acoelorraphe wrightii), Senegal date palm (Phoenix reclinata) and Formosa palm (Arenga engleri).
Solitary Trunked Palms
Cutting off the growing tip or crownshaft of a single-trunked palm species effectively kills the palm. When the growing tip is removed, the trunk wound cannot regenerate a new growing tip. Without foliage to photosynthesize light, the palm weakens and eventually the trunk and root tissues rot. If you cut off the top of a single-trunked palm, or a wind storms snaps off the top, the trunk will persist like a telephone pole. The trunk will topple after several months or years once the integrity of the trunk fibers soften. Examples of solitary trunked palms include Christmas palm (Adonidia merrilii), Mexican fan palm (Washingtonia robusta), royal palm (Roystonea regia) and cabbage palm (Sabal palmetto).
Since palms lack cambium, any wound created on their stems or trunks is not repaired. A partial cut into a trunk or puncture wound from a nail or bullet remains for the rest of the palm's life. These wounds dry out on the whim of the weather conditions. If rainwater or high humidity prevents the wound from drying and callusing, insect pests and fungal diseases can infiltrate the palm and cause more damage to the plant's vascular system. Prevent any wounds into the stems or trunks of palms. Monitor any wounds that occur as they may lead the palm to get sick and die from complications.