Sago Palm Care in Central Florida: Scale, Yellowing and Pruning

Sago palms are everywhere in Central Florida landscapes, and they are not palms. They are cycads, an ancient group of plants, and the difference matters for how they are fed, pruned and treated. Most of the sick sagos we see are suffering from one of three things: scale insects, a nutrient problem, or pruning that removed too much.

Scale: the white crust

The most serious sago problem in our area is an armored scale insect that coats the undersides of the fronds, then the tops, then the trunk, in a white crust that looks like a dusting of snow or flour. Left alone it kills the plant, usually within a year or two, and it spreads to nearby sagos.

• Check the undersides. Turn a frond over. The infestation starts there and is well established by the time it shows on top.
• Treat systemically and by contact. A systemic insecticide taken up by the roots, combined with horticultural oil on the fronds, is the usual program. Neither alone is enough against a heavy infestation, and it takes repeated treatment.
• Remove the worst fronds. Heavily crusted fronds are cut off and bagged, not composted. Leave every frond that is mostly clean.
• Treat every sago on the property and, ideally, coordinate with neighbors. Scale moves on wind and on the plants themselves.

A sago with early scale treated promptly recovers. A sago found white from base to tip is often too far gone, and removing it protects the others.

Yellowing

Yellow fronds on a sago mean one of a few things. Yellowing of the oldest, lowest fronds while the crown stays green is normal aging. Yellowing of the newest fronds, or yellow bands and spots across the whole plant, is a nutrient problem, most often manganese or magnesium in our sandy, often alkaline soils. A palm fertilizer with micronutrients, applied a couple of times through the growing season, is the right feed; regular lawn fertilizer is not. Our palm fertilizer guide applies to sagos as well. Overwatering also yellows sagos, and they want far less water than the lawn around them gets.

Pruning: less than you think

A sago makes one flush of new fronds a year, all at once, and it feeds that flush from the fronds it already has. Cutting green fronds off to make the plant look tidier, or to give it a bare-trunk look, removes the energy source for next year's growth. The plant weakens, the new flush is smaller, and repeated over-pruning kills it.

• Remove only fronds that are fully yellow or brown.
• Never cut into the crown or remove the new flush while it is unfurling.
• Remove offsets, the pups at the base, only if you want to; they can be replanted.
• Wear gloves and long sleeves. The frond tips are sharp, and every part of the plant is toxic to dogs and people if eaten.

Cold and site

Sagos handle Polk County winters well and are damaged only in a hard freeze, after which the fronds brown and a new flush replaces them in spring. Leave the damaged fronds until the flush appears. They prefer good drainage and full sun to part shade, and they suffer in a wet, low spot.

What we do

We treat scale, feed correctly and prune sagos as part of our tree and palm service. If a sago has gone white, request a visit soon; early treatment is the difference between saving it and replacing it. Our guide to palm trimming covers the true palms on the same property.