Jennifer Schultz Nelson
Extension Educator, Horticulture
Did you know you can buy prehistoric plants at your local discount store? The sago palm is such a plant. It is really not a palm at all, but a cycad. Cycads are an ancient group of plants that were around even before the dinosaurs, during the Permian Era over 200 million years ago.
Fossils of cycads are found on nearly every continent. They were the dominant type of plant life on this planet 150 million years ago, during the Mesozoic Era. Many species are now extinct, but those still existing have evolved very little for millions of years. For this reason, many people call cycads "living fossils".
Cycads are really unlike any other plants in the world. They are "dioecious" literally meaning "two houses". In this case one "house" is the male plant that possesses male flowers that produce pollen, and the other "house" is the female plant that produces ovules that when pollinated develop into fruits containing seeds. In both male and female plants, the flowers resemble large cones that emerge from the center of the plant. The male flower is cone or torpedo shaped, while the female flower is cabbage shaped.
Technically, the cycads are woody plants, though their tough stems contain little true wood and mostly storage tissue. Several cultures through the ages have used cycads as a source of starch for food, medicine, or ceremonial purposes.
However, all parts of cycads are poisonous. Their tissues contain neurotoxins that can cause paralysis and even death. With proper processing, these neurotoxins are removed, and the starch is safe for consumption. But slight errors can result in poisoning those consuming the end product. Researchers have investigated clusters of specific combinations of neurological symptoms in various cultures that appear to be related to ingesting cycad starches. In some cases the poisoning symptoms appeared immediately, in other cases symptoms developed latently, appearing up to 35 years after a single ingestion of a traditional cycad-based medicine.
The cycad most commonly produced commercially is the sago palm, also known as the king sago, palm cycad, or Japanese funeral palm. They are native to the southern most islands of Japan, and were traditionally used in funeral arrangements. The Japanese also export the leathery, plastic-like leaves for use in floral displays. Sago palms are slow growing when restricted in a pot, so they are also a favorite choice for bonsai.
Caring for a sago palm in zone 5 central Illinois is limited to potted plants or conservatory specimens at botanic gardens. In warmer climates like Florida, sago palms are a common fixture in home landscapes. Sago palms are hardy in zones 8 -10, though some argue they only will survive as far north as zone 9. When grown outdoors, sago palms may reach heights of ten to twelve feet with leaves four to five feet long.
Sago palms prefer very well-drained potting mixes, much like those used for cacti. Overwatering is a death sentence for sago palms. They need very little fertilizer, so slow-release granules or dilute liquid fertilizers are the best choice. Too much fertilizer will damage the sago palm's coralloid roots. These are specialized root structures that host blue-green algae. These algae fix nitrogen from the air and make it available to the plant.
The sago palm prefers bright light, and can easily tolerate full sun. It will live in semi-shaded conditions and produce larger leaves, but if there is too much shade, the plant may not produce new leaves at all. New growth typically occurs in the late spring and early summer.
My sago palm is very small, in a three inch pot. I know it will take years to grow into a specimen of any significant size, but I will enjoy watching my own slice of prehistoric landscape take shape.