Our soils in South Florida are poor in many of the most important elements palms need to grow healthy. That is why a good fertilization program is essential if you want to have healthy, good-looking palms. As a general rule it is better to fertilize the palms with smaller amounts of fertilizer every month or every other month than to fertilize them with heavier amounts two or three times every year.
This is by far the most common nutritional deficiency in palms growing in South Florida. This is basically due to the nature of our soils and the only way to correct this is to use good palm fertilizers with slow release Potassium. Potassium deficiency symptoms vary between the different palms species but initially the younger fronds are the ones that indicate this problem. The following photos will assist you in determining if this is happening to your palms. Some palms like the Royal palms need large amounts of Potassium otherwise they will show symptoms rather easily. The reason why the older fronds turn brown in palms with Potassium deficiency is because the palms takes the Potassium already in the older fronds and moves it to the new growth to compensate for the lack of this element in the soil. That is why we recommend not pruning fronds that are partially green because the palm can use them as a source for certain nutrients.
(Click on picture to review nutritinal Solutions)
Prevention and Treatment of Cold Damage
(From the University of Florida)