Planting Green Onions From Seed
If you love cooking with fresh scallions (also called green onions or spring onions), planting green onions from seed is one of the most rewarding garden projects you can start. Seeds are inexpensive, quick to germinate, and perfect for squeezing into small spaces, raised beds, and containers. I plant them in waves all season so there’s always a crisp, mild onion ready for snipping. Below, I’ll walk you through how to sow, grow, and harvest green onions from seed like a pro — with tips I’ve learned from many muddy-kneed seasons in the garden.
Why Grow From Seed
Seed-grown green onions are fresher, cheaper, and more flexible than store-bought bunches. You can pick the exact varieties you love, sow successions for a steady supply, and pull them at any size — from skinny baby scallions to full, juicy stalks. And since green onions mature quickly, they’re ideal for beginners and busy gardeners.
Know Your Green Onion Types
“Green onion” usually refers to bunching onions that don’t form a big bulb. These are Allium fistulosum varieties, prized for long white shanks and tender green tops. Some gardeners also harvest young bulbing onions (Allium cepa) early as scallions, but true bunching types keep producing longer and resist bulbing.
Reliable Varieties I Recommend
- Evergreen Bunching: Classic, bolt-resistant, tasty in any season
- Ishikura and Ishikura Improved: Extra-long white stalks, restaurant quality
- White Lisbon: Fast, mild, and dependable
- Guardsman: Thick shanks, great flavor, holds well in the garden
When To Sow
Green onions are cool-season friendly and forgiving. You can sow them early, often, and late, depending on your climate.
- Indoors: Start seeds about six to eight weeks before your last spring frost for a jump on the season
- Outdoors spring: Direct sow as soon as the soil can be worked; seeds sprout in cool soil but prefer warmth
- Succession sowing: Every two to three weeks from spring through late summer for a constant harvest
- Fall and overwinter: In many regions, a late-summer or early fall sowing gives you autumn and early spring scallions; with mulch or a low tunnel, I keep bunching onions going through winter in my zone 6–7 garden
Soil And Site Prep
Green onions have shallow roots and appreciate consistent moisture and nutrition but hate soggy feet. Choose a sunny site with six or more hours of direct light, and aim for loose, well-draining soil.
- Soil pH: Aim for 6.0 to 7.0
- Amendments: Mix in finished compost before planting; avoid fresh manure
- Drainage: Raised beds or mounded rows are ideal if your soil is heavy
- Containers: Troughs or pots at least 6–8 inches deep work beautifully with regular watering
Step-By-Step: Starting Seeds Indoors
Starting indoors helps you beat weeds and spring chill. I often multi-sow into cells so I can plant tidy clumps outside.
- Fill trays or cell packs with a fine, moist seed-starting mix and firm gently
- Sow about five to ten seeds per cell if you want clumps, or scatter thinly in open flats for later pricking out
- Cover seeds lightly with about a quarter inch of mix; press so seeds make good contact
- Bottom water so you don’t disturb seeds, and keep evenly moist
- Provide strong light for 12–14 hours daily; grow lights a few inches above seedlings prevent stretching
- Germination takes roughly seven to fourteen days; ideal soil temperature is around 68–75°F
- Trim tips lightly with clean scissors if seedlings flop; this encourages sturdier growth
- Feed with a mild liquid fertilizer (fish or seaweed) at half strength every week once true leaves appear
- Harden off for a week before transplanting by gradually introducing outdoor conditions
Direct Sowing In The Garden
Direct seeding is wonderfully simple and efficient for green onions.
- Rake the bed smooth and pre-water so the soil settles
- Draw shallow furrows about a quarter inch deep; I like rows six to eight inches apart or broad bands six inches wide
- Sow seed liberally; seeds are small and easy to under-sow, so don’t be shy
- Cover lightly and firm the surface so seeds have good soil contact
- Water gently and keep the top inch of soil consistently moist until seedlings establish
- Thin gradually once seedlings reach two to three inches tall; use thinnings as garnish
Spacing Strategies That Work
- Single file: Space plants about one inch apart in rows; this gives slim, uniform scallions
- Band sowing: Broadcast seed in a six-inch-wide strip and thin to half an inch to one inch; this maximizes yield in small spaces
- Multi-sow clumps: Transplant plugs with five to ten seedlings per cell, spaced six inches between clumps; harvest stalks from the outside and let the rest keep growing
Watering And Feeding
Green onions are happiest with steady moisture and a little extra nitrogen. Dry spells cause tough, hot-tasting stalks; soggy soil invites disease.
- Water aim: About an inch per week, more in summer heat or containers
- Method: Water early in the day at the base; avoid frequent overhead watering to reduce disease risk
- Mulch: A light mulch of chopped leaves, straw, or fine compost keeps moisture even and suppresses weeds
- Fertilizer: Scratch in a balanced organic fertilizer before sowing; side-dress with compost or give a diluted fish/seaweed feed every couple of weeks during active growth
Light And Temperature
Full sun is best, though a little afternoon shade in peak summer can keep stalks tender. Seeds germinate in cool temperatures but sprout fastest in the upper 60s to mid-70s°F. Established plants are remarkably hardy and shrug off light frosts.
Companions And Crop Rotation
Green onions tuck neatly between slower crops and help confuse pests with their aroma.
- Good neighbors: Carrots, beets, lettuce, strawberries, herbs, and brassicas
- Rotation: Avoid planting after other alliums (onions, garlic, leeks) to reduce disease and pest build-up
- Cover: Floating row cover deters onion maggots and leaf miners, especially in spring
Common Problems And Easy Fixes
- Slow or patchy germination: Soil dried out or too cold; keep consistently moist and use a board or fabric row cover to retain moisture until sprouting starts
- Damping-off: Seedlings collapse at the base; improve airflow, avoid overwatering, and use clean trays and fresh seed-starting mix
- Onion maggot: Tunnels at the base or sudden wilting; use row cover at sowing and rotate beds yearly
- Thrips: Silvery streaks or distorted growth; blast with water, encourage beneficials, and consider insecticidal soap if needed
- Downy mildew or leaf spots: Increase spacing, water at soil level, and avoid wetting foliage in the evening
- Bolting in heat or stress: Choose bolt-resistant varieties and maintain even moisture; harvest promptly if flower stalks appear
- Yellow tips: Usually drought stress, heat, or excess salts; flush with water and mulch to even out moisture
Harvesting, Storing, And Regrowing
Green onions are ready from baby stage to full size, so harvest to taste. Most bunching types reach harvestable size in about fifty to seventy days, faster in warm weather.
- Baby harvest: Pull at pencil thickness for the sweetest flavor
- Full size: Tug gently at the base or loosen the soil with a hand fork and lift the whole clump
- Cut-and-come-again: For multi-sown clumps, snip outer stalks at soil level and let the inner ones keep growing
- Regrowth: If you leave the roots and a sliver of white base, many plants resprout in mild weather
- Storage: Wrap unwashed scallions in a damp towel and keep in a breathable bag in the crisper for up to a week; or stand them in a jar with an inch of water, greens covered loosely
Saving Seed
Bunching onions are usually perennials or at least hardy biennials. They send up pretty pom-pom flowers in their second year. To save seed, let a healthy patch flower, bag a few blossoms to catch drying seed, and collect when the heads turn papery. Isolate different Allium fistulosum varieties if you want pure seed. Stored cool and dry, green onion seed remains most vigorous for one to two years.
My Step-By-Step Planting Recipe
Here’s exactly how I plant green onions from seed in my own garden for bumper harvests.
- Choose a bolt-resistant bunching variety and prep a sunny bed with compost
- Direct sow in early spring in shallow furrows a quarter inch deep, rows eight inches apart
- Cover and firm; water gently and keep the top inch of soil evenly moist
- Thin in stages to about one inch apart, eating the thinnings
- Mulch lightly once seedlings stand tall to lock in moisture
- Side-dress with compost or a light fish/seaweed feed every few weeks
- Sow again two to three weeks later in another band so you always have young, tender stalks coming
In my beds, I like a “confetti row” of scallions nestled along the edge of slower crops like tomatoes and peppers. They don’t mind the company, and I get fresh onions right where I’m working.
Frequently Asked Questions
How deep do I plant green onion seeds?
About a quarter inch deep is perfect. Shallow sowing plus firming the surface helps keep moisture around the seed.
How long do seeds take to germinate?
Usually seven to fourteen days. Warmer soil speeds things up; steady moisture is crucial.
What spacing gives the best yield?
For slim, uniform scallions, space about one inch apart. For maximum yield in small spaces, band-sow and thin to half an inch to one inch. For thicker stalks, transplant clumps six inches apart and harvest from the outside.
Can I grow green onions in pots?
Absolutely. Use a container at least six inches deep with quality potting mix, water consistently, and feed lightly. Trough planters are especially productive.
Do green onions overwinter?
In many climates, yes. Bunching onions can overwinter with mulch and return early, giving you the first greens of spring. In very cold regions, use a cold frame or low tunnel.
Final Thoughts
Planting green onions from seed is quick, simple, and ridiculously satisfying. With a little planning — a well-prepped bed, shallow sowing, steady moisture, and regular successions — you’ll have crisp, fragrant scallions at your fingertips for months. Start a row this week, tuck a few seeds into a pot on the patio, and make green onions a constant in your kitchen and garden. Once you’ve grown your own, you’ll never want to be without them.
