Sally Scalera

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

Palm nutrition and care

Dec. 10, 2005

For everyone with palms in their landscape, I have just recently learned some new information, and heard some old information that deserves repeating, that I want to pass along. I got the chance the hear Dr. Tim Broschat, Environmental Horticulture from our Ft. Lauderdale Research and Education Center, talk about Proper Palm Culture and Nutrient Deficiencies of Trees and Shrubs. 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 will slowly kill them. Turf fertilizers induce a potassium deficiency because the nitrogen is slow release whereas the potassium isn’t. After the potassium is gone the nitrogen is still being released and encouraging new fronds to be produced.

If you can’t use the right fertilizer, you are better off not fertilizing at all.

Palms normally have deficiencies that are similar to those of grasses. 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. I asked Tim what brands were good and he said those made by Nurseryman Sure-Gro Corp. (they are down in Vero Beach), Atlantic FEC (in Homestead), Howards, Hoodridge and Lykes are all good. I’m not sure what fertilizers all of the garden centers here in the county are selling but I do know that Growing Crazy up in Titusville and New Life Nursery in Melbourne carry the Nurseryman Sure-Gro 8-2-12 4% Mg or 8-4-12 4% Mg fertilizer.

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 could mean 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 palm 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 using a calibrated rotary spreader under the canopy area, the entire bed area or the entire landscape at a maximum rate of 15 pounds of fertilizer (that is the total fertilizer blend not just the Nitrogen like we do for turf) per 1000 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 leaves with green frond hanging down to the ground whereas the average coconut palm here in Florida only has 13 fronds. 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.

They say that the hardest part of learning something new is to forget the old but, luckily, I don’t have that problem. When one of our specialists shares what they have learned I find it pretty easy to replace the old information with the new. Now, I just have to get some of the fertilizer so I am ready for spring.