Common Palm Tree Problems

Hurricane Wilma has long been forgotten by many people.  But, the effects of the storm are still present or now appearing on many larger palms.  It requires more than a year for many palms to re-cycle all of their fronds.  Thus, some of the current lower fronds were present at the top of these palms when Wilma rolled through South Florida.  Twisted or cracked spears are now noticeable, as well as stress related fractures to fronds.  Penciling of the trunk, due to the reduced canopy, will now become visible and be noticeable for the life of the palm.
common palm tree problems miami broken heart palm
Broken heart stress fracture from windstorm damage
Lightning Strikes
South Florida is the lightning capital of the world.  Many beautiful palms are struck and killed every year.  They are especially vulnerable because they are often tall and have only one growing point, which if damaged, usually leads to death.  Symptoms of a strike include a sudden, almost over night browning and collapse of the canopy.  The spear most often remains upright.  Splitting, bleeding and burns may also be present.

Washingtonia robusta killed lighting strike palm tree
Washingtonia robusta killed by  lightning strike
Lethal Yellowing (click on image for larger view)
This is a fatal disease that affects many species of palms, most notably coconut palms.  This viral like disease is spread by leaf hoppers.  Preventative treatments of antibiotics are most effective.  If symptoms are detected early, antibiotics can be effective in slowing or preventing the further development of the disease.  Symptoms of the disease begin with the blackening of the inflorescence.  This is followed by pre-mature nut drop.  In the late stages, mature fronds yellow and die from the bottom upwards.  This may or may not take place rapidly.

Myndus common palm tree problems miami
Cocos nucifera infected with lethal yellow
Leaf hopper (Myndus crudus)
Palm Leaf Skeletonizer (Homaledra sabalella)
The caterpillars of this small moth feed on the upper and lower leaf surfaces of many palms, producing large quantities of `frass’ (fibrous excrement) that is often the first conspicuous sign of this infestation. The tissue between the veins or ribs is usually their preferred food, but they will also feed on the leaf stems, damaging & destroying the vascular tissue and causing the death of the entire leaf..
palm leaf
Golden Malayan coconut suffering from leaf skletonizer
Symptoms include wilting and a general decline in the appearance of the palm.  This is most often a gradual process.  This disease is fatal, with no prevention or treatment.  Conformation of the diseased palm may only be made by appearance of a “conch” or examination of the cross section of the trunk of the palm.  It is not recommended to replace an infected palm with another palm.
Ganoderma conch at base of Sabal palm
Graphiola leaf spot of false smut has become a common disease with the popularity to plant “date palms”.  This arid palm is much more susceptible to this disease in our sub-tropic climatic.  Overhead irrigation also increases this problem.  This disease can be characterized by round, dark lesions which produce a grayish-black fruiting bodies which rupture through the leaf surface, especially on the lower fronds.  Manganese based fungicides can be used as an effective control measure.
Graphiola on Medjoo
Graphiola on Medjool palm (Phoenix dactylifera)
“Frizzle Top” is a minor element that causes the death of many palms, such as Queen and Pygmy Date Palms.  New fronds appear smaller and chlorotic.  Following sets appear withered, scorched or “frizzled” in appearance.  Untreated, the palm die.  Other nutrients such as: nitrogen, potassium, magnesium, iron and zinc can cause palms to have a poor appearance or cause death.  Few of our native palms are planted in our landscapes.  These palms require little additional nutrients, but lack the beauty of non-native palm species.  These palms have diverse additional fertilization requirements.
frizzle-top-queenQueen palm (Syagrus romanzoffiana) suffering from “frizzle top”
Our sub-tropic climate is naturally wet and humid.  Then we add additional water through irrigation systems.  We make mistakes by planting palms that have highly different water requirements together in a single irrigation zone.  Then we add inexpensive water loving winter annuals next to arid loving palms.  Why should we wonder why our expensive palms looks bad of die.
Coco thrinax
Coco thrinax yellowing & fungus from excess H2O
Sooty Mold
Many homeowners call to complain about fronds or trunks of palms that appear black.  This fungal disease is a symptom of a far bigger problem.  This black mold seldom hurts the palm.  This mold is growing on the high sugar waste products of insects.  The real concern should be directed towards the insects which are adversely affecting the health of the palms.
Sooty mold
Sooty mold on European fan palm (Chamaerops humilis)
We do not always realize that insects are a problem to palms because the crown or fronds are too high above, obscuring their damage.  There are many aphids, borers, caterpillars, mites, scales and a whole list of other bugs that damage or kill palms.  Insects weaken palms, multiplying the effects of disease and nutritional problems.  Tall palms can not be sprayed due to their height, systemic insecticides provide control.Don’t worry, the palm tree specialists at PEST FREE can help!

insects on palm
Palm scale infestation of King Sago (Cycas revoluta)