Palm and tree questions
Why are my palms still yellow after fertilizing?
Usually the problem is not how much fertilizer goes down, but whether the palm can use it. In Southwest Florida, high soil pH and reclaimed irrigation water often lock nutrients away from the roots, and many landscape fertilizers are not built for palms.
Reviewed by Jeff Kaulbars, ISA Certified Arborist FL-10118A, Ptolemy Inc.
Check the soil before adding more
Soils and irrigation water here often run alkaline. High pH does not remove nutrients, it locks them up: iron and manganese can be in the ground and still out of reach when pH climbs above roughly 7.5. Reclaimed water raises pH a little more with every cycle. A soil test shows what the soil holds and what the pH is doing.
Check what is in the bag
Lawn fertilizer is heavy on nitrogen. On a palm, that can push growth the palm cannot support and deepen the deficiency you are trying to fix. Palms need a complete palm fertilizer, such as the UF/IFAS 8-2-12 standard with magnesium and micronutrients, in controlled-release form.
Check the timing
In sandy soil, smaller and more frequent feedings beat one large one. Summer rain leaches nutrients away, and many counties restrict nitrogen in the rainy season. Our position is that the productive window here runs roughly October through May.
Give it time, and do not cut above the line
Potassium and magnesium symptoms stay on the fronds that show them. A palm on the right program recovers by growing new, clean fronds over one to two years. The yellow fronds still hold nutrients the palm is drawing on. Prune to the 9-and-3 line and leave every frond above it.
If the top and the bottom of the canopy both look bad, or the color is reddish bronze rather than yellow, test for lethal bronzing.
Also asked
- What should I ask the company that fertilizes my palms?
- What product and analysis they use, how often they apply it, and whether anyone has checked the soil pH. A palm fertilizer program should name a complete palm fertilizer, not a lawn blend.
Read more
Sources: UF/IFAS EDIS palm nutrition series (EP263 to EP269).