The sago palm—scientifically known as Cycas revoluta, and also called the Japanese sago palm—features a crown of feathery fronds that growl in an attractive whorl from a rugged-looking trunk. These fascinating plants are not palms at all, but are really cycads—relatives of conifer and gingko trees—and have changed little in the 200 million years since the Mesozoic era. Sago palms, which rarely exceed 10 feet tall, flourish in Georgia and Florida, where they add lush tropical accents to yards and landscapes. These hardy plants grow with little difficulty; they do, however need to be properly fertilized. By following some basic guidelines for fertilizing your sago palm, you can help it thrive.
Feed your sago palm with a commercial slow-release granular fertilizer specifically formulated for palm trees in March, May, July and September. According to Tom Broome, president of the Cycad Society, a high-nitrogen formulation of 18-6-8 NPK is effective. The fertilizer must also contain the "minor elements"—such as iron, zinc, manganese, and magnesium—that cycads need to thrive.
Watch for "frizzle top," yellowing upper leaves or crown that are clear evidence of a manganese deficiency. Spray the leaves with a solution of one teaspoon of manganese sulfate per gallon of water.
Repeat the manganese treatment in one month, then spray again the following month.
Have a soil pH test performed to check the soil if your sago palm continues to develop deficiencies. Soil should be neutral—between 6.5 to 7.0; acidic soil makes sago palms more susceptible to problems absorbing nutrients, and leads to deficiencies. You can test the soil yourself, using a kit, or take a sample to your local county extension office for testing. Follow the recommendations for correcting soil pH.
Watch for yellowing of leaves, a sign not only of frizzle top but also an indication that your sago palm has may be over-fertilized. Fertilize your sago palm no more than four times a year, using amounts recommended on the label, and remove yellowing and browning fronds with a sharp pruning shears. New ones will emerge.
Watch for orange spots on the leaves, a sign of potassium deficiency. Correct by feeding with palm fertilizer.