iigiri tree

Photo: User:Henryhartley upload here by penarc — CC BY-SA 3.0 · source

Survives zone 5 through 8

Harvest calendar

Best planted in early spring after your last frost, or in fall before the ground freezes, depending on your climate.

⚠ Honestly: sources conflict. Some list the small berries as edible raw or cooked, but older horticultural accounts describe the fruit as bitter and disagreeable. Best regarded as an ornamental/bird-food berry and oilseed tree rather than a dessert fruit. Edible oil seeds · Needs summer heat to ripen.

Hardiness

Zone 5–8

Habit

Tree

Edible part

Seed, Fruit

Ripens

Autumn

Mature size

Tree 8–15 m

Light

Full sun to partial — needs summer heat to ripen

Soil pH

6.0–7.0

Environment

Temperate

Native range

Warm-temperate East Asia — China, Japan, Korea and Taiwan — in mixed forest, valley woodland and along riverbanks.

Status

Both wild and cultivated

Years to fruit

5+ yrs

Growth speed

Fast — 60–100 cm a year when young

Spacing

700 cm (276 in) apart — about 49 m² (527 sq ft) per plant

Leaf shape

Alternate, and the reason to plant the tree: large heart-shaped blades 12–25 cm with a scalloped-toothed edge, deep green above and glaucous beneath, on long red stalks carrying one to three small glands. The effect is close to tropical on a hardy tree.

Root system

Deep and wide-spreading, tolerant of poor and stony ground. It resents transplanting once settled, so move it small.

Fruit description

Pea-sized orange-red berries 7–8 mm in long hanging clusters on female trees, persisting well after leaf fall. ⚠ Sources genuinely conflict on the pulp: some list it as edible, older horticultural accounts call it bitter and disagreeable, and it is not a fruit to plant for the table. The seed is a different matter and is not in doubt — it runs to about 35% oil, more than 80% of it linoleic acid, and is pressed commercially in China for cooking oil and biodiesel.

Propagation

Seed, which needs cold stratification and germinates unreliably — the main thing holding the tree back commercially. Sow it fresh, and only where summers are long enough to ripen it in the first place. Dioecious, so both sexes are needed for fruit.

Pollination

DIOECIOUS — needs male and female plants

The edible parts listed above are a starting point, not a field guide. Identify a plant with certainty — ideally against a local authority — before eating any part of it, and read the full disclaimer. Spotted something wrong? Report it.