Palmetto tree
On a recent visit to Columbia, I was pleased to see so many palmettos growing around our capital city. South Carolinians take great pride in our state tree (Sabal palmetto), as well we should. Not only celebrated in our state’s history and on our state flag, this tree makes a handsome landscape plant.
Our beloved palmetto, also known as cabbage palm, is native to the coastal plain and thrives in that sandy soil. While palms may be more familiar along our coast, with the right mix of temperature, palm species and care, they can grow anywhere in South Carolina.
Cabbage palms are relatively cold hardy—10 F is about the coldest temperature they can handle without significant damage. Most of our state, including much of the Upstate, stays above this minimum temperature, according to the U.S. Department of Agriculture’s Plant Hardiness Zone Map. I am seeing more palmettos being planted in our red clay hills lately.
In colder areas of the Upstate, however, planting cabbage palms is risky. A safer option is to choose an alternative with greater cold hardiness: windmill palm or needle palm. Windmill palms form a single trunk covered in a dense layer of brown fiber and will often reach 20 to 30 feet in height. They are cold hardy on all but the highest mountains in South Carolina.
Needle palms, native to South Carolina, are considered the most cold-hardy palm species. Unlike palmettos and windmill palms, however, needle palms grow as dense shrubs and don’t produce an obvious trunk.
Plant palms in a well-drained location in the spring or early summer, giving them ample time to establish roots before winter. Young palms without a visible trunk cannot tolerate root disturbances and should only be transplanted from containers. Larger palms with developed trunks, often dug out of the wild, may have bare root balls but transplant quite well. Regardless of size, never plant any palm deeper than it was originally grown. Deep planting leads to root suffocation, nutritional problems, root-rot diseases and a slow death.
A tall palm needs support until its roots are strong enough to hold it upright. Attach braces with straps, not nails, to minimize trunk damage.
Water newly planted palms to keep the soil evenly moist for at least six months, and withhold fertilizer until new frond growth is observed, typically two to three months after planting. Once established, water deeply, providing one inch of water a week during the absence of rainfall.
Palms are adaptable to many soil types, but they need special nutrients. To keep your palms healthy, get your soil tested at a Clemson Extension office to discover which nutrients are missing. Then fertilize on a regular schedule with a slow-release, specialty palm fertilizer, often called “palm special.” Do not ring or pile fertilizer near the palm’s trunk. Instead, scatter it evenly under its canopy.
Palmettos and other palms require little pruning. Healthy, green leaves contain valuable nutrients and provide protection from cold damage. Remove only fronds that are badly damaged, diseased or completely dead, sawing them off near the trunk—don’t cut into the trunk, and never try to tear fronds free. Any damage to the trunk can lead to disease or insect infestation.
More details on selecting and caring for palms can be found in the fact sheet “Palms & Cycads” (HGIC 1019), available from Clemson Extension’s Home & Garden Information Center.
S. Cory Tanner is an area horticulture agent and Master Gardener coordinator for Clemson Extension based in Greenville County. Contact him at shannt@clemson.edu.