PLNTversePLNTverse
Plants › Edible vegetables

welsh onion (Allium fistulosum)

Allium fistulosum is a perennial herb that commonly grows in clumps and has hollow, cylindrical leaves.

LightAllium fistulosum is reported to grow in full sun.
WaterKeep the soil moist but well drained, with moderate watering in home cultivation.
TemperatureAllium fistulosum is frost hardy.
Track your welsh onion in the PLNTverse app
welsh onion illustration

Overview

Allium fistulosum is a perennial herb that commonly grows in clumps and has hollow, cylindrical leaves.

Origin and habitat

Sources differ on its exact wild origin, placing it broadly in temperate Asia, with more reliable accounts centered on an area from China to Siberia. It is a long-cultivated vegetable now grown in many parts of the world, with records of naturalization in some areas, while its original wild habitat remains uncertain. It is adapted to temperate conditions and cold tolerance, and can also be cultivated at higher elevations in tropical Southeast Asia.

Characteristics

Sources differ on mature height, reporting about 30–150 cm, while mature spread is 10–50 cm. The leaves are green, cylindrical, and hollow, with tightly overlapping leaf bases and sheaths forming a stem-like pseudostem; some descriptions note a slightly blue-green or powdery appearance. Sources differ in describing the flowers and flowering period: umbels arise at the tips of hollow flowering stalks, with numerous small white, greenish-white, or creamy-white flowers forming spherical to nearly spherical clusters, and flowering occurs from spring to summer. The fruit is reported to be a capsule that splits open when mature, with black seeds.

Light

Allium fistulosum is reported to grow in full sun.

Watering

Keep the soil moist but well drained, with moderate watering in home cultivation.

Temperature and dormancy

Allium fistulosum is frost hardy.

Growing medium and mounting

It is reported to grow in chalk, loam, or sandy soil that is moist but well drained, with cultivation recorded under acidic, neutral, and alkaline conditions.

Feeding

Continued fertilizing is reported to be possible during regrowth cultivation.

Propagation

It is reported that plants can be replanted with the roots and part of the white basal portion retained to regenerate leaves, and that lateral growth can also provide vegetative propagation.

Common problems

The plant is reported to be strongly cold tolerant and may retain leaves under snow cover; high temperatures promote swelling at the base, while flowering and seed production require exposure to cold conditions and may therefore be difficult in tropical climates.

Identification

Sources differ in their descriptions, but the leaves and flowering stalks are hollow and tubular, the plant does not form a large conspicuous bulb like a typical onion, and its relatively slender base commonly produces tillers that form clumps.

Photos

Allium fistulosum
📷 unknown · Public domain · source
Allium fistulosum
📷 Genmewcaugsa · CC BY-SA 3.0 · source
Allium fistulosum
📷 ajikang, some rights reserved (CC BY) · CC BY · source

Sources