Sally Scalera

Brevard County Horticulture Extension Agent
3695 Lake Drive -- Cocoa FL 32926 -- 321-633-1702

Important information for palms

May 17, 2008

A few years ago I learned some new information (plus some old information that is still important) and I realized as I drive around the county that it is probably time to share that information again. Many people plant exotic palms in their landscape, but I wonder how many realize how high maintenance pals are when it comes to their nutritional needs. I learned the following information from Dr. Tim Broschat who works in our Ft. Lauderdale Research and Education Center. Here are some of the important items he spoke about regarding palms.

  • Never use turf fertilizer within 50 feet of any palm!
  • If you use turf fertilizer on palms you could eventually kill them. Turf fertilizers induce a potassium deficiency because the nitrogen is slow release whereas the potassium isn’t.Therefore, after the potassium is gone the nitrogen is still being released and encouraging new fronds to be produced.
  • Palms normally have deficiencies that are similar to those of grasses so, therefore, if you need to fertilize palms that are planted in (or near) the lawn it is best to fertilize everything will 8-2-12 4%Mg or 8-4-12 4% Mg.
  • Some 8-2-12 4%Mg or 8-4-12 4%Mg are good, some don’t do anything and some are bad. Examples of some of the good brands would be Nurseryman Sure-Gro Corp. (they are down in Vero Beach), Atlantic FEC (in Homestead), Howards, Hoodridge and Lykes.
  • If a potassium deficiency exists then DO NOT remove any frond but those that are totally dead and brown. The removal of yellow fronds (which are moving potassium out and up to the new growth) will push the potassium deficiency up to the new growth. Too much pre-emergent herbicides can kill palms though it’s not understood why pre-emergent herbicides hurt palms more then post-emergent herbicides. Granular pre-emergent herbicides can last for up to six months and sprays for up to two months.
  • All palms naturally shed fronds quickly! A frond will go from green to yellow to brown in a matter of three days and that’s natural! So, if you have fronds that are yellowish and they are hanging on to your palm for more than three days (like a month or more) then that is a sign that your palm has a nutrient deficiency. Older fronds that are yellow are evidence of a Magnesium or Potassium deficiency.
  • Potassium deficiency is everywhere in Florida and the older fronds start off with yellow spots.
  • NEVER remove any living frond originating above the horizontal (9:00 a.m. to 3:00 p.m. when looking at the canopy like it was a clock.) The best policy though, is to ONLY remove totally brown fronds!
  • Do not attempt to pull off fronds that will not come off easily. This can result in trunk wounds that serve as entry points for diseases.
  • Never use climbing spikes on palm trunks for any reason!
  • When fertilizing, broadcast the fertilizer under the canopy area, the entire bed area or the entire landscape at a maximum rate of 1.5 pounds of fertilizer (that is the total fertilizer blend not just the Nitrogen like we do for turf) per 100 square feet every three months.
  • Most palms in Florida are not receiving the proper amount of nutrients and therefore don’t have the foliage they normally would. For example, healthy coconut palms can have 26 fronds with all of them a nice green color whereas the average coconut palm here in Florida only has 13 fronds and often the older fronds are yellow. For a Canary Island date palm the number of fronds in the canopy of a healthy palm is 130 and the number of leaves normally observed in the canopy of a Florida grown palm is 65.

If you have some non-native palms in your landscape then, clip out this article and file it away where you can refer to it whenever you need to. After all, green palms are the best.