According to Timothy Broschat and Alan Meerow in "Your Florida Landscape," palms comprise an important component of Florida horticulture and suffer quickly when grown in soils with mineral deficiencies. Nitrogen, potassium, magnesium and manganese often lacks in the Sunshine State's native soils. Appropriate application of granular "palm special" fertilizer provides palms the proper balance of nutrients to keep them healthy and fronds green. Following dosage and timing recommendations from horticulturists from the University of Florida reduces over-fertilization and leached pollutants into groundwater. Once a nutrient deficiency manifests visually, it can take a couple of years of proper fertilization to fully correct the problem.
Things You'll Need
Palm special fertilizer
Cup or fertilizer spreader
Purchase "palm special" fertilizer from a local garden center or horticultural supply center. Bags typically weigh 40 to 50 pounds a piece.
Read the fertilizer product label to learn of specific directions for determining dosage per the size of palm needing fertilizing. Ralph E. Mitchell, Cooperative Extension Agent in Charlotte County mentions a standard application dosage is 1 to 1 1/2 pounds of fertilizer applied for every 100 square feet the palm's fronds cover in area. For example, a foxtail palm with canopy measuring 10 feet by 10 feet (100 square feet) needs 1 to 1 1/2 pounds of granules scattered over its root zone.
Lift the bag of fertilizer and place it in a wheelbarrow. Load other project items in the barrow, too, such as rubber gloves, scissors to open the bad, a cup, portable scale, and spin-crank granular spreader. Cart the supplies to the palm.
Put on waterproof gloves before opening the bag and handling any granules. Your hand sweat mixes with the granules, makes it slippery and can cause a stinging sensation if any open scratches or cuts exist on your skin.
Fill a cup with granules and weigh it on a scale. Place the appropriate weight of granules into the spin-crank spreader for the size of the palm.
Turn the handle on the spreader to dispense the fertilizer granules as you walk around the palm. Scatter the granules widely and evenly under the spread of the fronds, even 5 to 10 feet beyond the farthest reach of the frond tips. This is where the actively growing roots grow underground from the palm trunk. Alternatively, scatter the granules by hand with the gloves on if you don't have a spreader.
Fertilize four times a year. General timing is in March, early June at the start of the rainy season, August and in October. Alternatively, Mitchell says fertilize six times a year, such as once in each of March, May, late June, mid-August, late September and November.
According to Michael S. Orfanedes, Urban Forester with Davie County, current University of Florida guidelines recommend a 100-percent slow-release fertilizer product with N-P-K ratio of 8-2-10 or 8-4-12. This replaces older recommended ratios, although keep in mind nitrogen and potassium is most often lacking in Florida soils, not phosphorus.
The palm fertilizer product needs to contain 4 percent magnesium and 2 percent of both manganese and iron. Also look to see that other trace minerals like boron, copper and zinc exist in the formulation, too.
Organic matter like compost, decaying leaves and wood mulch scattered over the sandy Florida soils help improve the soil's nutritional quality and helps slow leaching of fertilizers through the soil.
Do not apply palm fertilizer granules in a concentrated band near the palm trunk base. This is not where the majority of roots grow. Excessive fertilizer pellet concentrations, when activated with irrigation or rains, leads to root burn or damage from excessive salt levels in the soil.
- University of Florida IFAS Extension: Fertilization of Field-grown and Landscape Palms in Florida
- Mainscape Landscape Services: Palm Fertilizing and Nutrient Deficiencies
- University of Florida Extension (Charlotte County):Fertilizing Palms
- Davie County, Florida Government: Fertilization Tips for Keeping Palms Green & Healthy