Will Palm Trees Grow in St. Augustine, Florida?

Cold Hardiness

• Palm trees in St. Augustine have to be able to tolerate sporadic periods of frost and below-freezing temperatures. Sudden cold spells cause more damage than gradually cooling weather because plants do not have time to adjust to the winter temperatures. More damage occurs to palm trees during cold weather when the humidity is low or the wind is blowing strongly. Drought-tolerant palm trees withstand cold temperatures better than other palms because they are adapted to living on small amounts of water. Since cold air settles in low-lying areas, palm trees on higher ground do not suffer as much winter damage. Palms planted near buildings and walls are also sheltered from cold weather.

Cold Damage

• The buds, or hearts, of palm stems and the roots grow more slowly when the weather is cold, which weakens the trees and makes them susceptible to diseases. Do not remove any fronds with green tissue or the nutrients remaining in the fronds will be lost to the tree. Remove only fronds that are completely brown and dry. Immediately spray all the fronds and hearts with a copper fungicide that contains the equivalent of 4 percent metallic copper to help prevent diseases. Use 4 to 6 teaspoons of copper fungicide per gallon of water and spray every seven to 10 days. Use the stronger rates and more frequent intervals for palm trees that are severely damaged. If the soil around the palm tree has frozen, soak the ground with the copper fungicide mixture to minimize the chance of root diseases. If the vascular tissue that conducts water in the trunk of the palm tree is damaged, the tree usually dies. The initial sign of damage appears when some or all of the fronds collapse during the first warm spell after freezing temperatures. The tree may survive for a few years but will continue to decline.

Palms With Pinnate Fronds

• Pindo or jelly palm (Butia capitata) is the hardiest of the palms with pinnate fronds. It grows up to 15 feet tall with a single trunk and blue-green fronds. It is hardy in USDA zones 8 through 10 and has moderate salt tolerance. Canary Island date palm (Phoenix canariensis) is a striking specimen tree that grows up to 40 feet tall. It has dull deep green fronds and is moderately salt-tolerant. Another large date palm, Phoenix dactylifera, has gray-green fronds and is highly salt-tolerant. Both grow in USDA zones 8b through 11.

Palms with Palmate Fronds

• Cabbage palm has a single trunk and grows up 40 feet tall. The dull green fronds are costa-palmate, which means they are palm shaped with a midrib that runs through the center of the frond. It is hardy in USDA zones 8a through 11. Most sabal varieties are moderately to highly salt-tolerant. Windmill palm (Trachycarpus fortunei) has dark green palmate fronds with silvery undersides. The single fiber-covered trunk grows up to 20 feet tall. It is hardy in USDA zones 8a through 10a and can tolerate light snow. It is moderately salt-tolerant.