By Norman Winter
Horticulturist
Central Mississippi Research & Extension Center

Palms can give a tropical feeling around the pool or patio like no other plant can. I used to poke fun at people who tried to grow certain plants far outside their preferred habitat, then I realized that palms made me one of those people.

There are at least two palms native coastal southeastern states and Texas. One is Sabal minor, or shrub palmetto, and the other is Rhapidophyllum hystrix, or needle palm. The fact that they are native to these areas is an indication that they are very cold hardy.

Sabal minor makes a fine addition to the landscape. I do get eyebrows raised when I speak of its virtues. This shrub-type palm with large palmate leaves has been documented to withstand temperatures of minus 15 degrees.

Cold hardiness of palms and some trees and shrubs is determined by how much hardening off has occurred before the cold weather starts. In other words, if it was 80 degrees the day before the minus 15 cold snap, forget it.

Opinions differ about the cold hardiness of palms. For instance, some reference books say the Sabal palmetto is more cold hardy than the Sabal minor. While it may be prettier, I have not found it to withstand temperatures anywhere near what our native Sabal minor can withstand. You see this palm around Charleston, S.C., and Savannah, Ga.

The needle palm forms clumps and usually doesn't even blink when the temperature reaches zero. Some people have had theirs defoliate at minus 16 degrees but bounce right back in the spring. These palms usually reach about 4 feet in height.

The palm most often found in nurseries in Central Mississippi is the windmill palm, Trachycarpus fortunei. Since living in Mississippi, I have seen them suffer at 7 degrees but recover the next spring. These can reach 40 feet high, but you are most likely to find them in the 20-foot range in mid-Mississippi. Two were planted in 1907 in the Hidecote garden in Scotland where it annually gets 7 degrees. They have only reached 15 feet in height there.

A super palm for the South and South-central Mississippi is the Mediterranean fan palm, or Chamaerops humilis. It is a clumping fan palm that is almost as hardy as the windmill palm. It tolerates a wide range of conditions and makes an excellent container plant.

Washingtonia filifera, or California fan palms, are easy to find and hardy to about 15 degrees, while the Washingtonia robusta, or Mexican fan palm, is only hardy to about 22 degrees.

When many think of palms, they think of those with a feather-type of leaf, or pinnate, rather than palmate, or needle leaves. The most cold hardy of feather palms is the Pindo, or jelly palm known as Butia capitata. This South American palm has been known to withstand temperatures in the middle teens on rare occasions. It can reach 30 feet, but is usually shorter in South Mississippi. The leaves are enormous and can cover half a backyard.

One of the prettiest and easiest to find feather palms is the pigmy date palm, Phoenix roebellinii. It is not the least bit cold hardy. I keep mine in a container by the pool during the growing season and indoors in the winter. I have had my oldest one for about 14 years and it is close to 9 feet tall.

If you want to plant a palm for the landscape, now is a good time so that it can get established before the winter. If you are going to push the cold hardiness limits, consider the microclimates around your home where the palm might receive protection from northern winds and cold fronts. Wrapping trunks during severe winter weather also can help dramatically.