The Foolproof Way to Plant Onions from Sets
(And Why It’s Better Than Starting from Seed for Most Gardeners)
If you’ve ever felt intimidated by growing onions, you’re not alone. Between the different planting methods and timing windows, it’s easy to overthink it. But here’s the good news—planting onions from sets is one of the most beginner-friendly ways to grow a successful crop. In this post, I’ll walk you through why sets are my go-to choice, where to find them, and exactly how to plant and care for them in your garden.
What Are Onion Sets?
Onion sets are small, immature onion bulbs that were grown from seed the previous season and harvested early, then cured and stored through winter. When you plant them in spring, they’re ready to leap into full bulb production.
Why Choose Sets Over Seeds?
While onions can be grown from seed or transplants, sets offer several key advantages—especially for busy or first-time gardeners:
✅ Much faster to mature than seed-started onions
✅ Less time and effort—no need to start indoors months in advance
✅ More forgiving in cool soil and unpredictable spring weather
✅ Minimal thinning compared to seed-sown rows
In short, if you want onions without the fuss, sets are your friend.
Where to Buy Onion Sets
Most local garden centers, feed stores, and plant nurseries carry onion sets in early spring. Look for:
Firm, dry bulbs about the size of marbles
No mold, soft spots, or green sprouting
Options like yellow, white, and red onions, or sweet vs storage varieties
If shopping online, choose a reputable company and opt for short-day or intermediate-day onions if you're in the South (like us here in North Georgia), and long-day onions if you're farther north.
How to Plant Onion Sets
🌱 Timing:
Plant as soon as the ground can be worked in early spring, typically 2–4 weeks before your last expected frost.
🌿 Soil Prep:
Onions love loose, well-drained soil rich in organic matter.
If you're no-till, a surface mulch with compost and super tea is great.
For tilled rows, add compost and a balanced organic fertilizer if needed.
🔪 Planting Steps:
Loosen the soil 4–6 inches deep.
Plant sets root-side down, pointy tip up.
Space each bulb 3–4 inches apart in rows spaced 10–12 inches apart.
Press gently into the soil and cover just so the tip is peeking out.
Avoid burying them too deep—shallow planting encourages quicker growth and larger bulbs.
Caring for Onion Sets
Water consistently, especially in dry weeks.
Mulch between rows to suppress weeds and retain moisture.
Side-dress with compost tea or a nitrogen-rich fertilizer a few weeks after planting if growth stalls.
Keep beds well-weeded—onions don’t compete well for light and nutrients.
As bulbs begin to swell, you’ll see the soil around them crack. That’s a good sign!
When to Harvest Onions
Once the tops begin to yellow and fall over, stop watering. Let them sit for a few days, then pull and cure them in a dry, shaded spot for 2–3 weeks before storing.
Final Thoughts
Planting onions from sets is truly a set-it-and-forget-it method—perfect for the busy homesteader or anyone just getting started. Whether you’re aiming for a summer harvest of sweet onions or a long-storing winter stash, onion sets give you a strong head start with minimal effort.
Have you tried growing onions from sets yet? Let me know in the comments or tag me on Instagram when you do—I'd love to see your garden grow!