Dioscorea polystachya
Chinese yam
Common names: Cinnamon vine, Nagaimo
At a glance
- Light
- Full sun
- Spacing
- 40 cm, rows 80 cm
- Lifespan
- Perennial
- Planting
- Apr–May
- Harvest
- Oct–Nov
- Hardiness
- Hardy down to −20 °C
- Water need
- Medium
Description
The Chinese yam (Dioscorea polystachya) is a hardy climber from East Asia that produces a long, pencil‑shaped tuber. The tuber tastes like yam when raw or cooked. Unlike most yams, it is one of the few species whose tuber can be eaten raw, though the raw skin contains fine crystal needles that can irritate the skin; gloves and a brief rinse are advisable. The shoots climb up to several meters on supports and in late summer produce small “breeding tubers” in the leaf axils from which new plants grow. These breeding tubers and the persistent root system make the plant spread readily on loose soil; a root barrier or container culture prevents unwanted spread in a bed. Once established, the Chinese yam reliably returns year after year and yields abundantly in autumn.
Care instructions
Plant tuber pieces or breeding tubers in mid‑April to late May (week 16 to 21) in deep, loose soil once the danger of frost has passed. Provide a sturdy support of at least 2 m from the start, as the shoots grow quickly and become heavy. Keep the soil evenly moist but avoid waterlogging, and mulch in summer to prevent drying out. In autumn, collect fallen breeding tubers if you wish to prevent spread in the bed. Harvest begins in October (week 40) when the leaves yellow; the tuber can be carefully dug out with a spade as it breaks easily. Wear gloves when peeling the raw tuber, as the skin can irritate the skin.
The care notes were machine-translated from German.
Garden year
PlantingApr–May
HarvestOct–Nov
Soil & site
Soil pH
Soil type
well-drained, humus-rich, nutrient-rich, sandy
The Chinese yam likes loose, deep soil in which the long root tubers can expand unhindered. Heavy, compacted soils slow growth and make harvesting difficult. Sandy, humus-rich soil with good drainage and plenty of organic matter is ideal; the plant won't tolerate waterlogging.
Feeding
Medium feeder
Months
Apr–Jul
Before planting, work ripe compost deep into the soil so that it is directly available to the roots. During the main growth phase from May to July, give a trowel of compost or diluted plant liquid feed every few weeks. From August, reduce the nutrient supply so that the tuber can ripen in peace.
Overwintering
The tuber stays in the ground, hardy, as long as it sits deep enough and the site doesn't become permanently wet. A mulch layer of leaves or straw protects against severe frost, especially in the first year in place. Above ground, the vines die back in autumn and shoot again from the tuber in spring.
Propagation
Methods
- Offsets
- Division
The easiest way to propagate the Chinese yam is via the small aerial tubers (bulbils) that form in the leaf axils in late summer and can be sown directly. Alternatively, in early spring, separate a piece of the main tuber, as long as it carries at least one eye. The young plants need a climbing support at first and even moisture until they have established well. Sowing from seed is possible, but takes much longer to the first harvest.
For your garden
Grow Chinese yam yourself
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