Allium fistulosum Seeds | Welsh Onion Evergreen
LATIN NAME: Allium fistulosum
COMMON NAME: Welsh Onion
Plant Profile
The Welsh onion never forms a fat storage bulb at all; it is a clump of hollow, cylindrical leaves rising from a slim, white-based stem, grown entirely for the green top and the tender white shaft. That is why it is sold as scallion or spring onion and why a cook can snip it all season without lifting a single bulb. The ‘Evergreen’ type is the ever-bearing white bunching form kept by seed houses for continuous cutting.
Where a bulb onion swells storage leaves, Allium fistulosum keeps its leaves fistular and hollow, and the base stays a narrow, blanched cylinder rather than a globe. The plant is a perennial that builds a slowly widening clump from short rhizomes, and the leaves are blue-green, upright, and far finer in texture than those of a globe onion. A few small, white, globular umbels appear in late summer if the plant is left to flower.
Unlike the biennial bulb onion, the Welsh onion is a true perennial that shrugs off cold and returns from the base each spring, which is why it is the allium of choice for cut greens through the cool months. Its chromosome set and bulb-less habit separate it cleanly from Allium cepa, and the two will not cross in the garden. The clump simply grows taller and whiter as the season warms.
Scatter the small black seed on the firm surface and press it in lightly, covering with the thinnest veil of soil or vermiculite because the seed needs light to sprout evenly. Thin early so air moves through the young row and the leaves stay upright.
Science & Biotechnology
The green onion’s bite is milder and grassier than a storage onion’s, and the reason lives in a different balance of sulphur compounds plus a lower load of the eye-watering precursor.
When the leaf is cut, the alliinase system releases volatile sulphur compounds led by methanethiol and related disulphides that give the fresh, green, slightly pungent note of a scallion rather than the deep heat of a bulb onion. The profile is closer to chives than to a storage globe, which is why the Welsh onion is used raw or barely cooked.
Uses & Benefits
Breeding and lab work on Allium fistulosum show its pyruvic acid values sit well below those of pungent bulb onions, a useful marker for the mild eating quality that cooks want in a scallion. The lower the pyruvic load, the sweeter and gentler the green, and ‘Evergreen’ was selected to hold that mildness while staying vigorous.
This is a greens onion first, used wherever a bright allium note is wanted without the bulk of a bulb. The same plant supplies the stir-fry, the garnish, and the salad through much of the year.
Snip the outer leaves an inch above the base and the clump regrows, giving a cut-and-come harvest that can run from spring until the hard freeze. The white lower shaft is the prized part in many Asian dishes, where it is chopped into pancakes, broths, and fried rice. Because the plant is perennial, a single spring sowing can supply a family for several years with almost no further work, which is why it anchors the backyard allium plot in cold climates.
Hilling soil around the base blanches the stems to a tender white, the form sold in bunches as negi or spring onion. The blanched shaft has a sweeter, softer bite than the green top and is the traditional component in hot pots and savoury pancakes across East Asia.
Growing from Seed
Start the clump from a fine seed in a loose, fertile, well-drained medium of loam, compost, and sharp sand, and keep it evenly moist until the seedlings stand. The plant wants sun and steady water but dislikes a wet crown in winter.
Begin thinning when the seedlings show their third true leaf, pulling the weakest to leave a finger’s width between plants; reach a final spacing near eight centimetres once they carry six true leaves and a slender, pencil-thick stem. Divide the mature clump every couple of springs to keep the centre from dying out.
Our Take
I grow ‘Evergreen’ in a dedicated cut-green row and never run out of onion tops. The Onion Allium cepa gives the bulb crop, while the Garlic Chives seed Allium tuberosum, the Chives Allium schoenoprasum, and the Egyptian Onion china Allium x proliferum keep the allium bed busy from spring to frost.
Related Reading
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