Sago Palms – Pros, Cons, & Care
Article by: Jessica Warren, ANR Agent – Camden County
Sago palms are a popular, and generally low-maintenance, plant here in Coastal Georgia, but many homeowners understand little about these plants or how to care for them. For a start, sago palms are not actually palms at all, but a type of prehistoric gymnosperms called cycads. It is believed that cycad species were the main food source for herbivorous species of dinosaurs. Sago palms are more closely related to conifers than palm trees.
Sago palms are native to Southern Japan. They are long lived and slow growing perennials, growing two to three inches per year or less. Sago palms may be single or multi-stemmed, starting out shrub-like and maturing to a more tree-like form. Their size at maturity can be up to 15 feet tall and 10-12 feet wide. Thick crowns of dark, glossy green leaves are characteristic of sago palms. Leaves can be up to 4-5 feet long and 9 inches wide. Sago palms can be grown in containers or in the landscape in Coastal Georgia. They can be grown in USDA hardiness zones 8-11. They require well drained soil and full sun to partial shade. Sago palms need to be spaced 4-6 feet apart when planted in groups and are drought resistant once established.
Sago palms are dioecious and reproduce through cones instead of flowers, which are found in the center of the plant. Plants are either male or female. Female cones resemble a furry, yellow globe and produce bright orange seeds that are roughly two inches in diameter. The male cone is a large yellow cone that can grow up to two feet long. Cones are produced in the summer. In addition to cones, sago palms can reproduce through pups. Pups are new plants growing off the main plant. Pups can be removed or left on the main plant based on personal preference. Leaving pups in place will result in a multi-stemmed plant. If pups are removed, this should be done early on. If you would like to grow new plants from the pups, place them in clean soil and keep them moist (but not wet). It may take several months for the pups to develop roots.
There are a handful of issues that can affect sago palms in Coastal Georgia, with manganese deficiency being the most common and often most severe. Many people confuse manganese with magnesium (which can be found in Epsom salts), but they are two different elements. Manganese deficiency in sago palms may be caused by insufficient manganese levels in the soil, a high (alkaline) soil pH which limits manganese availability, root rot, poor drainage, too much or too little water. The first signs of manganese deficiency are yellow and/or brown spots or streaks on the leaves. Young leaves may appear distorted and small and may rapidly turn from yellow to brown. The foliage on the top half of the plant may become distorted, discolored or dead in severe cases.
Cycad scale are the biggest pest offender of sago palms. Cycad scale are insects that have a hard, waxy white armor that feed by sucking out the plant’s sap. Cycad scale infestations start on the underside of leaves, and the first symptom is usually yellow blotches on the fronds. Once an infestation becomes severe, the scale will cover all surfaces of the plant and desiccate it. Severe infestations can be lethal.
Horticultural oil is usually effective in treating an infestation and is the recommended treatment option. Mealybugs are another waxy, white, sucking insect. They infest all parts of the plant but prefer new tender growth. Mealybugs often congregate together giving a cotton-like appearance. A large number of predatory insects feed on mealybugs so it is important to protect these helpful predators by not using a broad-spectrum insecticide. Insecticidal soap or horticultural oil is recommended. Both mealybugs and scale can cause a secondary infection of black sooty mold. Black sooty mold is harmless to the plant but is often what gets a homeowner’s attention. Black sooty mold grows on the sweet, sticky waste (called honeydew) of sucking insects like mealybugs and scale. It will grow anywhere that the honeydew falls, including driveways, fences, mailboxes and cars. Black sooty mold can be sprayed off with a water hose, but the insect issue must be treated to keep it from returning.
In addition to nutrient deficiencies and pest issues, sago palms are susceptible to cold injury. Though tolerant to short periods of cold temperatures, sago palms suffer foliar damage during frosts and cold snaps. Cold damaged fronds have evenly browned sections with most of the damage on the upper leaves. This is often mistaken for a disease. It’s important not to remove damaged fronds until all danger of frost has past, as upper leaves can protect lower leaves from further damage. Damaged fronds can be pruned after the threat of frost has passed and an undamaged new flush should emerge over time.
I can’t discuss sago palms without discussing their toxicity. All parts of the sago palm are toxic to wildlife, humans and pets. Seeds are exceptionally dangerous. Sago palms have no value to pollinators, and the male plants are considered moderately allergenic to humans. In addition to their toxicity, exercise caution with physical contact as the leaves are quite spiky and can be painful.
If you’re looking for a cycad for your landscape, I would recommend a coontie instead of a sago. Coonties are native to Southeastern Georgia as well as Florida and offer a lot more bang for your buck. Coonties are not spiky and difficult to interact with but have a similar shape and appearance to their cousin the sago. Coonties do not struggle with nutrient deficiencies and have less pest pressures as they are naturally adapted to our soils, insects and climatic conditions. Coonties are the only host plant for the beautiful Atala butterfly (that doesn’t normally occur this far north so don’t get your hopes too high on this one). Coontie seeds are used as food by some birds and mammals, but like their relatives, are toxic to humans and pets.