Scout (F1) Onion Seed

Scientific name

Allium cepa

Site and soil

Give onions full sun and fertile, well-drained ground with a pH of 6.0–7.0. Sandy loam is ideal; on heavier soil, grow them in raised beds or raised rows so water drains away.

Day length

Onions start to form bulbs when days reach a certain length, and summer days get longer the farther north you are. Short-day onions are for southern latitudes; intermediate- and long-day onions are for the middle and northern states. Check the day-length type of each variety before you choose.

Days to maturity

Counted from direct sowing. Transplants mature roughly 10–15 days sooner.

Starting transplants

Long- and intermediate-day types: start seed indoors about 8–12 weeks before the last frost, one seed per cell in 128-cell trays or three seeds per cell in larger plugs, covered with 1/4" of mix. Set plants out 4–6" apart in rows 12–18" apart; long, floppy tops can be trimmed to about 5" at planting. Short-day types: sow from mid-September to mid-October, 6–8 weeks before transplanting, or sow 1/4" apart in a nursery bed with rows 6" apart and move the seedlings at 4–6 weeks.

Cold protection

If nights will drop below 50°F (10°C) after planting, cover young transplants with medium-weight row cover to keep them warm and help them root in; take it off once nights stay above 50°F.

Direct sowing

In long- and intermediate-day regions, sow as soon as the soil can be worked in spring, usually April or early May; in short-day regions, sow in mid-September. Sow about 2 seeds per inch in a 2" wide band, 1/4–1/2" deep, in rows 12–18" apart. Thin to 1 1/2–2" for the heaviest total yield on rich soil, or to 3–4" for bigger bulbs.

Overwintering

Use varieties suited to overwintering and sow from mid-August to early September, either direct or in flats for transplanting. Where winters freeze, protect plants with row cover; in the coldest areas, grow them in a low or high tunnel under cover.

Seeding rate

At 20 seeds per foot in rows 18" apart: about 1 oz. per 25 ft., 1,000 seeds per 50 ft. and roughly 580,000 seeds per acre.

Care

Onions have shallow roots, so keep weeds down with light, shallow hoeing and supply at least 1" of water a week, especially while bulbs are swelling. Good air movement and crop rotation help limit leaf diseases.

Harvest and curing

Harvest when the necks soften and about half the tops have fallen over. Cure in a warm, airy place out of direct sun so the bulbs do not turn green, or leave them in the field for a few dry days and then finish indoors. Curing takes about two weeks, until the necks are tight and the tops completely dry; cure indoors if the weather is very hot or wet. Short-day onions can also be pulled young with their green tops and sold in bunches as fresh spring onions.

Storage

Once dry, trim the tops and roots and store the bulbs in mesh bags or shallow crates just above freezing at 65–70% relative humidity.

Transplants per ounce

About 4,900 plants per oz. of seed, or about 78,750 per lb.

Seed size

Seed is sized for even spacing.

Packet

250 seeds.

Seeds per lb.

About 110,100 on average.