Scallions are one of the most forgiving crops a beginner can grow, and they reward you fast. You can pull your first crisp stalks in as little as eight weeks from seed, snip a few stems whenever a recipe calls for them, and keep the same clump producing for months. They take almost no room, thrive in a pot on a sunny step, and even regrow from the rooted ends you would otherwise compost. This guide covers planting scallions from seed, transplants, or kitchen scraps, keeping them healthy, and harvesting them at their peak.
What Scallions Are and How They Differ From Green and Spring Onions
A scallion is a young, mild onion harvested before it forms a fat bulb. The true scallion is Allium fistulosum, also called the bunching onion or Welsh onion. Unlike a regular onion, it never swells into a round bulb at the base; it stays as a straight white shank topped with hollow green leaves, and the whole stalk is edible.
Scallion and green onion are simply two names for the same thing. Spring onion is where the confusion creeps in: a spring onion is usually an ordinary bulbing onion (Allium cepa) pulled while still immature, so it carries a small rounded bulb and a slightly sharper bite, and left in the ground it keeps growing into a full onion. A true scallion never bulbs up.
So if you want a quick, cut-and-come-again crop that returns year after year, grow Allium fistulosum. You can also harvest the young green leaves of a standard onion and use them like scallions, but that plant will eventually shift its energy into forming a bulb.
When and Where to Plant Scallions
Scallions are cool-season growers that handle light frost, so they are one of the earliest things you can get into the ground. Start sowing under cover in late winter, then sow outdoors as soon as the soil is workable in spring, generally a few weeks before your last frost. Because they mature quickly, keep sowing short rows every three to four weeks through midsummer for a steady supply rather than one big glut.
Give them a sunny, open spot. Like all alliums, scallions want full sun, ideally six or more hours a day, though in hot southern gardens a little afternoon shade helps them cope. The soil should be loose, fertile, and free-draining. Work in a couple of inches of compost or well-rotted manure before planting, since their shallow roots feed close to the surface and benefit from the steady moisture organic matter holds.
These tall, narrow plants barely cast a shadow, which makes them ideal for tucking between slower crops such as parsnips or carrots until those crops need the room. The scallions may even help mask the scent that draws carrot rust flies.
Planting Scallions From Seed, Transplants, or Sets
Direct sowing is the simplest route. Rake the bed fine, then mark out a shallow furrow about a quarter to half an inch deep, with rows roughly four inches apart. In dry weather, water the bottom of the furrow before sowing to cool it and aid germination. Sow the seed thinly, cover lightly, and water in; seedlings usually emerge in one to two weeks. Once they are up, thin them so plants sit about an inch apart, or sow in small pinches of four to eight seeds to grow them as thicker bunches.
To get a head start, sow indoors eight to ten weeks before your last frost. Plug trays work beautifully: fill them with a general potting mix, sow a small pinch of seeds per cell, and keep the mix evenly moist and warm, with a seedling heat mat to speed germination. Transplant each plug as a cluster once roots show at the drainage holes, setting the clumps two to four inches apart. Sowing in clusters this way gives you dense, restaurant-style bunches that harvest together.
Transplants and sets skip the seed stage and get you to harvest faster. Move nursery or home-raised transplants outdoors two to four weeks before the last frost, spacing them one to three inches apart; before planting bare-root transplants, trim the roots to about half an inch and the tops to roughly four inches so they settle in without flopping. Onion sets, the small dormant bulbs sold for spring planting, go in about an inch deep and quickly send up shoots you can harvest young. Just remember that sets of a standard bulbing onion will eventually try to form a bulb, so harvest the greens early if scallions are what you are after.
How to Grow Scallions in Containers
Few crops suit pots as well as scallions. Because they have shallow roots and never bulk up underground, a container only needs to be about six to eight inches deep, and almost any width works since you can pack the slim stalks close together. A wide, shallow trough, or even a recycled salad tub with drainage holes, holds a generous bunch.
Fill it with a free-draining potting mix rather than garden soil, which compacts in pots. Sow seed a quarter inch deep, or tuck in transplants an inch or two apart. Water is the main thing to watch: pots dry out far faster than open ground, so check the surface daily and water whenever the top inch feels dry, keeping the mix moist but never waterlogged. A monthly drink of diluted liquid feed keeps potted scallions producing, since frequent watering flushes nutrients out of the limited soil.
Regrowing Scallions From Kitchen Scraps
The cheapest scallions you will ever grow come from the bunch in your fridge. When you cook with store-bought scallions, save the white root ends, leaving about one to two inches of the white shank with the roots attached.
For the water method, stand the rooted ends upright in a small jar with just enough water to cover the roots, not the whole stalk, and set it on a bright windowsill. New green growth appears within a day or two, and you can begin snipping fresh stalks inside a week. Change the water every two or three days, or sooner if it turns cloudy, to stop the roots rotting and going slimy. Water alone carries no nutrients, though, so a windowsill jar only sustains the plant for a few cycles before the regrowth thins and weakens.
For a crop that keeps going, plant the rooted ends in soil instead, in a pot or out in the garden. Set them so the white base sits just below the surface, keep the soil moist, and they will root in and send up new shoots every couple of weeks. This works indoors under a grow light as well as outdoors, which is why the soil method is the better choice for more than a quick novelty harvest.
Watering, Weeding, and Feeding Scallions
Scallions are sensitive to drought because their roots are shallow and cannot chase moisture deep down. Aim for about one inch of water per week, soaking the bed thoroughly rather than sprinkling lightly. Sandy soil needs watering more often, since an inch sinks and dries fast, while heavier clay holds moisture longer; push a trowel in to check how far down the soil is damp. Watering in the morning lets the foliage dry through the day, lowering the risk of fungal disease, and steady moisture also reduces bolting.
Weeds are the biggest early threat. Young scallions are slim and easily smothered, so weed gently and often while the plants are small, and a light mulch suppresses weeds and holds moisture at once. Once the stand fills in and the stalks crowd together, weeds struggle to gain a foothold.
Because you grow scallions for their leaves rather than a bulb, they respond well to nitrogen. A balanced or nitrogen-rich liquid feed every few weeks during active growth keeps the stalks lush, or top-dress with compost for a slower release.
Blanching for a Longer, Milder White Shank
The white portion of a scallion is simply the part shielded from light, and you can grow more of it on purpose through blanching. As the green tops reach about six inches, mound a couple of inches of loose soil around the base of the stalks, repeating every two or three weeks. Hidden from the sun, that buried section stays pale, tender, and sweeter than the sharper green leaves. Blanching is optional; many gardeners happily cook with both the white and green parts and skip it, but if you prize long white shanks for a particular dish, hilling up the soil is how you get them.
Common Pests and Problems
As members of the allium family, scallions carry an oniony scent that deters many pests, so they are rarely overwhelmed. A few issues are still worth knowing.
Yellowing or wilting leaves are the most common complaint, and they almost always trace back to water. Too much, and the roots sit soggy and rot; too little, and the leaves wilt and pale. Match your watering to your soil and weather before reaching for anything else.
Bolting is the next frequent worry. Heat, cold snaps, or erratic watering stress the plant into throwing up a flower stalk, and once it flowers it stops putting energy into tasty leaves. Snip off that stalk, called a scape, as soon as it appears. The scapes and young blooms are mild, faintly oniony, and perfectly edible in a stir-fry or as a garnish, so nothing goes to waste.
Among insects, thrips and aphids appear most often and can be knocked back with a strong jet of water, then insecticidal soap or neem oil if they persist. Onion maggots, the larvae that tunnel into the base, are best prevented with crop rotation and floating row covers. Slugs and snails chew the soft greens and can be trapped or baited. On the disease side, damp, crowded conditions invite white rot, downy mildew, and botrytis leaf blight, which show as spotting, yellowing, or collapse at the base. Wide spacing for airflow, morning watering, and rotating where you plant alliums each year prevent the large majority of these.
When and How to Harvest Scallions
Scallions are ready to pick remarkably fast, often within 50 to 70 days of sowing, and spring crops are frequently usable in eight to ten weeks. You can harvest them at almost any stage, but they reach full size when the stalks are about a quarter to half an inch thick and the green tops stand 10 to 12 inches tall, with a white shank at least two inches long.
You have two harvesting styles. For a continual supply, treat them like chives: snip a few green stalks an inch or two above the soil and leave the roots and base in the ground. The clump quickly pushes up fresh shoots, giving you a true cut-and-come-again crop for weeks. For a full harvest, pull whole plants instead, loosening the soil first with a trowel or fork so the stalks lift cleanly rather than snapping off at the soil line. Pulling the day after rain, or after a good watering, is easier and leaves the flesh firm. Lift the largest plants first to give the smaller ones room to size up.
Because true bunching scallions are perennial, a clump left in place regrows and comes back year after year in mild climates, which is what makes a single planting so productive. Where winters turn hard, mulch the crowns with straw in fall to carry them through, though prolonged hard freezing can still kill them. Once cut, scallions keep only a few days in the fridge, so harvest them as you need them, or stand the stalks upright in a jar with a little water, or slice and freeze them for cooked dishes.
Plant Once and Snip for Months
Scallions deliver more flavor for less effort than almost anything in the vegetable patch. Sow a short row, tuck a pot on the windowsill, or root a few grocery-store ends in soil, then keep snipping while the clumps keep growing. Start a fresh row every few weeks, lift the biggest stalks first, and you will have crisp, homegrown scallions on hand from spring straight through fall.