Japanese sago palm plant: how to care for the Asian evergreen

Cycas revoluta, the Japanese sago palm plant, is one of the most distinctive and regal of exotic plants. Resembling a short, squat palm, it has a rough-textured trunk topped by a big shuttlecock of lush emerald fronds that are sometimes 1.5-metres long. Depending on where you live, it can be grown as an indoor or outdoor plant.

Its common name – Japanese sago palm – is a misnomer, since it isn't a palm at all. It is a type of cycad, which makes it akin to a living fossil. The cycads are ancient plants that have stocky, woody trunks and large, stiff evergreen leaves, which are usually pinnate. Dating back to the early Mesozoic Era, 200 million years ago, they were so common when the dinosaurs roamed the earth that the Jurassic Period is sometimes referred to as the Age of Cycads.

Being primitive, it seems appropriate that the Japanese sago is incredibly slow growing. Largely unplagued by pests or diseases, it can be very long lived, and takes its time – sometimes a century – to form a tall branched tree. In its native subtropical habitat (of China, Taiwan, and Japan, including the Ryukyu Islands), it can grow to 7 metres or more.

C. revoluta is also widely referred to as, simply, the sago palm. But this is another misnomer, since the true sago is Metroxylon sagu, a palm from New Guinea. Both plants are harvested to produce the food sago (or sagu) – a tapioca-like starch used to make pancakes and other puddings. However, M. sagu, is the primary plant farmed, favoured for being fast growing and non-toxic. Conversely, C. revoluta grows at tortoise pace and demands a lengthy food extraction process, since it is poisonous.

In the right conditions, the Japanese sago palm is a low-maintenance long-lived stalwart for the house or conservatory. Planted in a pot, it can be wheeled outside for the summer months, and, in mild areas, is fine growing in the ground. In the microclimate of Brighton, for example, C. revoluta is a common sight, with mature specimens consuming the entirety of front gardens. So, be warned, that these Jurassic plants can achieve dinosaur proportions, albeit very slowly.

Where to put a Japanese sago palm plant

Indoors: Avoid direct south-facing sun and deep shade; a west or east-facing room is usually best. Don't place it near a draught, heat source, or dehumidifier.

Outdoors: Cycas revoluta can be planted outside in places that don't plummet past -5°C and enjoy warm summers (London or Cornwall, for instance). Alternatively, plant in a pot that can be moved under cover for winter.

How to grow a Japanese sago palm plant

• Site it in sheltered sun or semi-shade outside; in bright indirect light indoors. Avoid south-facing sun, which can scorch the leaves.
• Soil should be very well-drained; sandy soil is perfect.
• Shield from extremes of temperature by keeping the plant away from draughts and radiators.
• Don't move the plant when new fronds are emerging. Japanese sago palms do very little, then suddenly – like a teenager – will put on a growth spurt for a few weeks.
• Water more during the plant's rare periods of growth; otherwise, only water when the upper layer of compost feels dry in summer; water sparingly in winter. Water from below to avoid getting water on the crown.
• Humidity is appreciated. In a room that has average to low humidity, regularly mist the leaves (especially in summer) or sit the plant on a tray of water and pebbles.
• Feed once a month during spring and summer.
• Before winter, unless you live in a mild area, wheel potted sagos under cover, and gently wrap sagos in the ground in bracken or straw (tying the leaves tightly can stain them, so do it lightly).
• Repot in spring, if necessary, as long as the plant hasn't started sending out new fronds. Use a free-draining potting compost.

Sago palm pests and diseases

Usually unaffected by pests and diseases outside. Mealybugs and scale insects can be a problem in a conservatory.

Safety

Highly toxic to pets and people, if eaten, so avoid sagos if you have a puppy that gnaws on everything.

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