Scallion

A scallion is not a young onion, though many gardeners treat them as the same thing. True bunching onions — Allium fistulosum — never form a bulb no matter how long you leave them in the ground. They stay slender, grow tall green tops, and can be harvested at any size from pencil-thin to finger-thick. An ordinary bulbing onion harvested young will give you something that looks like a scallion, but the flavor is sharper and the white part tends to be shorter.

The real advantage of scallions in a home garden is speed and succession. Sixty days from seed to table is fast enough that you can sow a new row every three to four weeks from early spring through midsummer and have a continuous supply well into fall. Direct-sow them four weeks before your last frost — they can handle cold soil better than most crops — and plant them densely, about two inches apart. Thin as you harvest.

One common mistake is planting a single large bed all at once and then watching half of it bolt in a heat spell. Scallions tolerate cool weather well but can send up a flower stalk quickly when temperatures swing from cold to hot in spring. The stalk makes the core woody and the flavor harsh. Succession planting solves this — you're never relying on a single bed to carry you through the season, and any planting that bolts is replaced by the next sowing.

If you buy scallions at the grocery store and the roots are still attached, you can replant the white ends in soil and they will resprout. Cut the green tops an inch above the roots, set the bases in a pot or a garden row with the roots buried, and they'll send up new growth in a week or two. This is not a long-term production method — the regrowth tends to be thinner and tougher after the second or third cutting — but it buys you a few weeks of green onions while your next sowing is coming up.

Scallions tend to be unbothered by most pests, though onion maggots can tunnel into the base of the plant and cause it to rot from the roots up. You'll see yellowing, wilting tops and a soft, foul-smelling base. Row cover from sowing through the first few weeks helps prevent the adult flies from laying eggs near the plants. Pull and discard any affected plants immediately — do not compost them.

Harvest when the tops are six to eight inches tall, or let them grow longer if you prefer a stronger flavor. Pull the whole plant rather than cutting the top — a scallion that is cut and left in the ground may resprout once, but the new growth tends to be thin and the core turns woody. Better to pull it, replant the next succession, and keep the cycle moving.