by Matt Lollar | Sep 7, 2019
A couple weeks ago, I was on a site visit to check out some issues on Canary Island Date Palms. The account manager on the property requested a site visit because he thought the palms were infested with scale insects. He noticed the issue on a number of the properties he manages and he was concerned it was an epidemic. From a distance, lower fronds were yellowing from the outside in and the tips were necrotic. These are signs of potassium deficiency with possible magnesium deficiency mixed in.
Transitional leaf showing potassium deficiency (tip) and magnesium deficiency (base) symptoms. Photo Credit: T.K. Broschat, University of Florida/IFAS Extension
Nutrient deficiencies are slow to correct in palm trees. It’s much easier to prevent deficiencies from occurring by using a palm fertilizer that has the analysis 8N-2P2O5-12K2O+4Mg with micronutrients. Even if the palms are part of a landscape which includes turf and other plants that require additional nitrogen, it is best to use a palm fertilizer with the analysis previously listed over a radius at least 25 feet out from the palms. However, poor nutrition wasn’t the only problem with these palms.
Upon closer look, the leaflets were speckled with little bumps. Each bump had a little white tail. These are the fruiting structures of graphiola leaf spot also known as false smut.
Graphiola leaf spot (false smut) on a Canary Island Date Palm. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Graphiola leaf spot is a fungal leaf disease caused by Graphiola phoenicis. Canary Island Date Palms are especially susceptible to this disease. Graphiola leaf spot is primarily an aesthetic issue and doesn’t cause much harm to the palms infected. In fact, the nutrient deficiencies observed in these palms are much more detrimental to their health.
Graphiola leaf spot affects the lower fronds first. If the diseased, lower fronds are not showing signs of nutrient deficiencies then they can be pruned off and removed from the site. All naturally fallen fronds should be removed from the site to reduce the likelihood of fungal spores being splashed onto the healthy, living fronds. A fungicide containing copper can be applied to help prevent the spread of the disease, but it will not cure the infected fronds. Palms can be a beautiful addition to the landscape and most diseases and abiotic disorders can be managed and prevented with proper pruning, correct fertilizer rates, and precise irrigation.
by Ray Bodrey | Oct 12, 2016
Figure 1: Palm damage after storm event.
Credit: Edward F. Gilman, UF/IFAS.
A common question after a tropical storm or hurricane event is will my palm tree recover? Palms grow different from other trees, so there’s definitely a different way to care for them post-storm.
The growing point of a palm tree is the bud, located in the top of the tree. This is where the palm fronds emerge. If this bud area becomes damaged, no new leaves will develop and unfortunately the tree will die. If by chance the palm tree has multiple-stemmed trunks, the undamaged trunk(s) should survive. Often times palm trees are so tall that it is very difficult to visibly determine if the bud has been damaged. Time will tell.
It’s important to wait at least 6 months to see if palms develop new growth. Palms usually rebound slowly after a storm. It may take a couple of years before the palm tree produces a full canopy of fronds. If a damaged palm tree is determined to be in peril and current rainfall is not sufficient, it’s important to irrigate three times a week for at least six weeks to assist in recovery.
After the storm strikes, it may be beneficial to perform pruning of the canopy. Start by removing any hanging broken or dead fronds that could be hazardous to people or property. It’s a good idea to remove any fronds that are covering the bud, as well. This will allow new fronds to form. Leave any bent green fronts attached. These fronds still have vital nutrients that the tree is utilizing. Once the frond turns brown, then it is safe for removal.
Storm damage cleanup is extremely dangerous, even for professionals. During cleanup after the storm, remember that safety comes first. Some general safety tips are essential, as in, do not work alone. It’s important to keep a well-stocked first aid kit too. Avoid overexertion at all costs. This is the most common cause leading to injury. Be sure to survey the area, identify the hazards and have a plan for the cleanup. Above all, create a safe area to work within.
Palm tree recovery from storms is a slow process, so please be patient and safe. Contact your local county extension office for more information.
Supporting information for this article can be found in the following the UF/IFAS publications:
“Assessing Damage and Restoring Trees After a Hurricane” by Edward F. Gilman, Mary L. Duryea, Eliana Kampf, Traci Jo Partin, Astrid Delgado & Carol J. Lehtola: http://monroe.ifas.ufl.edu/pdf/Hort/Assessing_Trees_After_Hurricane.pdf
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by Mary Salinas | Feb 4, 2014
The freezing rain last week across the panhandle left icicles hanging from street signs, rooftops, trees, shrubs and palms. Many people now wonder if their palms will survive the assault of the hard freeze. The chance of survival depends on the following factors:
- the most important consideration is the species of palm; a few of the most cold tolerant that are more readily available are pindo palm, mule palm, European fan palm, Chinese fan palm, needle palm, cabbage palm, and dwarf palmetto
- whether the palm is in an area protected by other vegetation or buildings
- proper fertilization with 8-2-12-4 has been followed
- palms have been properly pruned, i.e. only dead fronds have been removed from the crown (overtrimming by removing green fronds is a stress to the palm)
Icy pindo palm. Photo by Mary Derrick UF IFAS.
The best approach is to leave the palm alone until all danger of frost or freeze is past. Avoid the temptation to remove any of the dead fronds; they will help insulate and protect the meristem, or bud, that will produce new shoots.
If the palm is not too tall, in the spring check to see if the spear leaf (the newest frond that usually stands straight up and has not opened) can be easily pulled out. If the spear leaf does not pull out, the likelihood that the palm has survived is good. Don’t despair if the spear leaf does pull out as the meristem below it may still survive. The best strategy in that event is to remove the dead spear leaf and treat the bud area below the spear leaf with a copper fungicide to reduce the chance of infection of the bud. Be sure to use a copper fungicide and not a copper fertilizer, like copper sulfate.
Once spring comes and you find that the palms have survived, don’t be alarmed if the first new frond is deformed or has dead tips. The fronds that follow will most likely be normal. The palm will be building its depleted food reserves with new leaves so do not remove any fronds that have any green on them whatsoever. All green tissue is making food for the palm and helping it to recover from the cold stress. Only remove fronds that have completely died and have no green tissue.
When temperatures warm and the palms are actively growing, apply a palm fertilizer with the formulation of 8-2-12-4 with micronutrients.
For more information please see the following University of Florida IFAS publications:
Palms for North Florida
Cold Damage on Palms
Fertilization of Field-grown and Landscape Palms in Florida
Pruning Palms
