Udo

Photo: Uncle Carl (カールおじさん) — CC BY-SA 3.0 · source

Survives zone 4 through 8

Harvest calendar

Ripens: Shoots harvested in spring

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

A commonly cultivated food crop in Japan, grown for its young shoots rather than any fruit — the taste is often described as a lemony asparagus. Traditional Japanese cultivation forces roots in dark, humid underground pits ("udo muro") to blanch the shoots pale and mild before harvest.

Hardiness

Zone 4–8

Habit

Herb

Edible part

Shoot

Ripens

Shoots harvested in spring

Mature size

Herbaceous perennial to 1.8–2.7 m in a season; dies back to the crown each winter

Light

Full shade to part shade

Soil pH

5.5–7.0

Environment

Temperate woodland

Native range

Japan, Korea, China and eastern Russia — woodlands and grassy slopes.

Status

Both wild and cultivated

Years to fruit

2–3 yrs (shoots, not fruit)

Growth speed

Very fast — 2 m from a dormant crown in a single season

Spacing

100 cm (39 in) apart — about 1 m² (11 sq ft) per plant

Leaf shape

Large, compound, heart-shaped leaflets

Root system

Thick perennial rootstock that resprouts each spring; dies back completely in winter.

Fruit description

Not the crop and not worth eating: small blue-black berries in loose sprays in autumn, left to the birds. Udo is grown for the blanched spring shoot, which is earthed up or forced in the dark and eaten raw in slivers or lightly cooked — crisp, and tasting of lemon and fennel.

Propagation

Division of the roots, or seed (needs cold stratification, best sown fresh).

Pollination

Insect-pollinated; irrelevant to the crop, which is a shoot. Plants are raised from division in any case.

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.