Cycas revoluta Seeds | Sago Palm
LATIN NAME: Cycas revoluta
COMMON NAME: Sago Palm
Plant Profile
Sago palm is not a palm at all but a cycad, a group that has been on earth since before the dinosaurs and has changed very little since. The plant forms a stout, rough trunk up to 1.5 m in old specimens, crowned with a rosette of stiff, glossy, dark green fronds that unroll from the centre like fern croziers.
Growth is slow and rhythmic: a flush of new leaves appears once or twice a year, hardens over a month, and then the plant rests. A trunk a metre tall may be a century old, which is why large specimens are expensive and why seed-grown plants are the only sane way to start.
Cycas revoluta comes from southern Japan and the Ryukyu islands, where it grows on cliffs and in open coastal scrub. It is dioecious, with male cones and female seed-bearing structures on separate plants, and the female produces a crown of woolly orange seeds in autumn.
Science & Biotechnology
Cycads are gymnosperms, and they sit on a branch of the plant tree that separated from the line leading to flowering plants more than 300 million years ago. That is why their anatomy looks archaic: motile sperm, a vascular system unlike a conifer’s, and leaves that unfurl rather than expand.
The plant is toxic in every part, and the toxin is worth knowing. Cycasin, a methylazoxymethanol glycoside, is carcinogenic and hepatotoxic, and it is present in the seed and the stem. Sago starch is extracted from cycad trunks in parts of Asia, but only after repeated washing and cooking that remove the compound, and the process is not one to attempt casually.
Cycads also host nitrogen-fixing cyanobacteria in specialised roots, which is unusual among gymnosperms and allows them to grow on poor, thin soil. That symbiosis is one reason the group has persisted on cliffs and in scrub where competition is low.
Uses & Benefits
Sago palm is grown as an ornamental for containers, courtyards and conservatories, where its architectural shape earns its space. It is also a bonsai and penjing subject in Asia, and large specimens are used in tropical-style planting.
The starch from the trunk has been a famine food in Japan and China, and the seeds are used in some traditional preparations after processing. Commercially the plant is a nursery crop, sold as seed, as offsets and as mature specimens. Every part is toxic to dogs and cats, and the seed is the most dangerous part.
Growing from Seed
Soak the seed for 24 to 48 hours in warm water, then sow 2 cm deep in a gritty, free-draining mix at 25-30°C. Germination takes two to six months and is uneven, so start more seed than you need. Fresh seed germinates far better than stored seed.
Grow the seedling in a deep pot, since the plant makes a long taproot before it makes leaves. Water freely in summer and sparingly in winter, and never let the pot stand in water. Give full sun to bright light, and protect from frost, which damages the fronds at about -4°C. Repot only every three or four years, since the plant resents disturbance.
Our Take
A slow, statuesque plant for a pot or a courtyard, and one to keep away from anything that chews, because every part of it is toxic.
Related Reading
Gardeners who grow Sago Palm often pair it with these related subjects: