Palm Trees - Cold Hardy Choices
How to choose cold-hardy palms and revive palms damaged by a freeze
By Howard Garrett
Special Contributor Dallas Morning News published 3/24/11
Since North Texas landscapes have so many brown, unsightly palms after the deep freeze in February, they are a common subject of concern. Are they dead, readers ask? Where should we look for signs of life?
You will not harm the plant by removing frozen, brown fronds. Cutting them away, however, does not contribute to the healing process of a living plant. If there is no green showing at the base of the leaf stems (also called petioles), the plant is probably a goner.
Some palms are hardier than others. Our average winter lows do not kill most palms sold in the Dallas area, but lows in the single digits, and several days when the thermometer did not rise above 32 degrees, took a toll on marginal palms.
If you are holding out hope that a palm is alive, drench the root zone out to 6 feet from the trunk with Garrett Juice, prepared according to the container’s directions (to make Garrett Juice from scratch, find the recipe at www.dirtdoctor.com. Then wait. As the soil and air warm, new leaves should appear if a palm is alive.
There are three top choices for cold hardiness: the native sabal palm, the Japanese windmill palm and the shrubby needle palm. These palms are showing little to no freeze damage this spring.
Needle palm (Rhapidophyllum hystrix). A trunkless palm that looks more like a shrub; cold-hardy to minus-10 degrees.
Texas sabal palm (Sabal texana). A slow-growing palm with spineless leaf stems; cold-hardy to 10 degrees.
Japanese windmill palm (Trachycarpus fortunei). A slow-growing, small, tough palm with dark green foliage; cold-hardy to 5 degrees.
Pindo palm (Butia capitata). A beautiful blue-green palm that is cold-hardy to between 12 and 15 degrees. This selection made the second-choice list because some specimens came through the harsh winter just fine.
Mediterranean fan palm (Chamaerops humilis). Cold-hardy to 15 degrees. It is a nice, small palm that had no problems in protected spots but had significant cosmetic damage in some gardens.
California fan palm (Washingtonia filifera). California fan palm is cold-hardy to 15 degrees. This palm is superior to the commonly sold Mexican fan palm (W. robusta).
Mexican fan palm (Washingtonia robusta). Mexican fan palm is cold-hardy to 18 degrees. Don’t plant it in Zone 8 and colder without special protection. Mexican and California fan palms look similar, so check the label before buying one.