Chinese Yam "Nagaimo/Cinnamon Vine" (Dioscorea polystachya) Tubers – Cold-Hardy Perennial Vine, Crisp Mucilaginous Root, Edible Raw or Cooked

Minimum: 5+ Tubers

The Yam You Eat Raw

Most yams and root vegetables demand cooking before they're edible. Nagaimo doesn't. Grate it raw and it turns into a slick, mucilaginous slurry eaten over rice in Japan, or slice it thin for a crisp, apple-like crunch in salads. This cold-hardy perennial vine, also called cinnamon vine for its faintly spiced aroma, produces a long, starchy tuber equally at home cooked into soups or grated raw, and once established, the vine returns reliably year after year with little care.

Who Grows Chinese Yam "Nagaimo"?
The home cook wanting fresh nagaimo for tororo, okonomiyaki, or Japanese home cooking.
The perennial vegetable gardener wanting a plant-once, harvest-for-years crop.
The cold-climate gardener needing a yam-type crop that survives winters.
The vertical gardener with a trellis or fence looking for a productive vine.

What This Cold-Hardy Root Vine Actually Is
Dioscorea polystachya, called Chinese yam, nagaimo, or cinnamon vine, is a twining perennial vine native to East Asia, grown for its long, cylindrical tuber reaching 2 to 3 feet deep in loose soil. The vine climbs readily on a trellis, producing heart-shaped leaves and, in some conditions, small aerial bulbils usable for propagation. The tuber's flesh is white, crisp, and mucilaginous, a texture prized in Japanese cuisine, where it's grated raw into tororo or sliced for a crunchy addition to salads and pickles; it's equally usable cooked into soups, stir-fries, or simmered dishes. Unlike tropical yams, this species is genuinely cold-hardy, with the vine dying back each winter and the tuber persisting underground to resprout in spring. Hardy in zones 5 through 9, considered invasive in parts of the eastern US, so check local status before planting.

In the Kitchen & Garden

• Grated raw tororo: Grate fresh tuber into a sticky topping for rice or soba.
• Sliced raw salad: Slice thin for a crisp, apple-like crunch, dressed with soy and vinegar.
• Cooked soups and stir-fries: Add cubed tuber to soups or stir-fries, where it softens but keeps some bite.
• Okonomiyaki binder: Use grated nagaimo as a traditional binder in Japanese savory pancakes.
• Perennial vertical planting: Train the vine on a trellis for a productive, edible screen.
• Bulbil propagation: Collect aerial bulbils where they form to start new plants alongside division.

Growing Chinese Yam Tubers

• Start method: Plant whole tubers or sections directly in loose, worked soil in spring.
• Timing: Plant after last frost once soil warms.
• Depth: Plant tuber sections 4-6 inches deep in loosened, rock-free soil for straight growth.
• Sunlight: Full sun to part shade.
• Soil: Deep, loose, well-drained soil is essential; heavy or rocky soil forks tubers.
• Support: Provide a trellis, fence, or other vertical support for the twining vine.
• Watering: Consistent moisture through the season supports strong tuber development.
• Growth cycle: Vine dies back each winter; tubers persist underground and resprout in spring.
• Harvest: Dig tubers in fall after the vine dies back, taking care with the long, deep root.
• Containment: Consider a container or root barrier where spreading habit isn't wanted.
• Hardiness: Reliable to zone 5; a true perennial where winters allow tuber overwintering.
• Invasive note: Regarded as invasive in some eastern US regions; check local regulations first.

Before You Close This Page
This is the yam you can eat without cooking it first. Chinese Yam delivers a crisp, mucilaginous tuber equally at home grated raw into tororo or simmered into soup. It's a genuine cold-hardy perennial, returning from the same root year after year once established, and the twining vine doubles as an edible screen. Give it deep, loose soil and vertical support, and it asks for little else. Grow the root that proves not every yam needs a stove.