The sago palm (Cycas revoluta) is actually a cycad, not a palm tree. The tree existed when dinosaurs roamed the Earth over 150 million years ago during the Mesozoic era, according to Floridata. This small tree flourishes in tropical and sub-tropical areas. It can also withstand temperatures that dip down to 15 degrees F for short periods. A sago palm normally reaches a height of around 12 feet at about 50 years of age.
Maintaining the overall health of your sago palm helps prevent pests and disease. It should be planted in well-drained, sandy, alkaline soil to prevent crown fungus from forming. Sago palms flourish in partial shade, which helps prevent unsightly leaf spot. Leaf spot is a fungal infection that often occurs on foliage in full sunlight. Though it causes spotting, it will not kill your tree. Application of fungicides will easily control leaf spot fungus and eradicate it from your tree.
Sago palms require abundant manganese in their soil. Acidic soils rarely provide these trees with sufficient amounts and should be avoided as a planting location. A sago palm that suffers from a manganese deficiency will have yellowing leaves. Young foliage will unfurl in a dry and crinkled condition, instead of healthy and green. An extreme deficiency will result in your tree's death.
Manganese Deficiency Treatment
Spraying the foliage of a sago palm with manganese sulfate monthly for three months over the summer will help the tree recover. Apply a powdered manganese nutrient to the soil surrounding the tree in the spring and fall to meet your tree's manganese requirements.
Asian Cycad Scale
An insect called the Asian cycad scale (Aulacaspis yasumatsui) widely afflicts sago palms. The scales encase themselves in a protective covering on foliage to suck nutrients from the trees, which gradually turns the leaves white. The insects can kill a sago palm within one year of infestation. It is estimated that 3,000 insects can infect 1 square inch of the sago palm, according to the University of Florida.
Hosing a sago palm off with heavy streams of water every few days has shown limited success in controlling Asian cycad scale. Using oils such as volck oil, dormant oil, fish oil and summer oil has shown promise. Systemic insecticides such as acephate, disyston and dimethoate also kill the insects. Experiments with predatory insects and wasps are currently underway, according to the University of Florida.