Robellini palm (Phoenix roebelenii), also called pigmy date palm, is well adapted for growing in the ground in USDA hardiness zones 9 through 11. Cooler regions should grow this palm inside containers for protection in winter. Palms receive cold damage when temperatures drop below 30 degrees Fahrenheit. If temperatures remain in the freezing zone for too long, the plant may die. When frost damage occurs, the palm is susceptible to bacterial infections. Gardeners have several treatment methods they can use to bring the palm back to health, if the damage is not severe.
Wait until all signs of frosts and freezes have left your region before treating or pruning the robellini palm. Pruning the palm before the weather warms will result in further and more severe injury if another frost or freeze occurs.
Sterilize your pruning tools by wiping the blades with alcohol before using them on the robellini. This will cut down on the transfer of new bacteria and diseases to the open pruning wounds. Sterilize the tools before using them on another plant.
Trim away only completely brown fronds with no green remaining on them. Allow any slightly green fronds to remain on the tree for photosynthesis purposes, as it helps the robellini in its recovery from the cold damage.
Spray the robellini with a fungicide mixed with a spreader sticker, per the label instructions. Thoroughly saturate the palm's trunk and foliage, including the center bud where new growth develops.
Repeat the fungicide/spreader sticker application in 10 days to two weeks. Thoroughly saturate the entire palm again, including the center bud.
Spray the foliage with a water-soluble, liquid nutrient for palms after the fungicide applications are completed. The liquid nutrients sprayed on the robellini foliage during the warm growth season will help it recover to a healthy state. Continue spraying young trees up to 3 years old monthly.
Apply a granular palm fertilizer, per the package instructions, under older robellini canopies in late spring and again every three months, according to the University of Florida. Do not allow the fertilizer to touch the trunk and water it in well after applying. Regularly fertilized trees are healthier and have more strength to survive damage from cold weather.