Onion Sets vs Transplants vs Seeds: Which Should You Choose?
By Ada Jones · Updated October 2026 · 7 min read
Short answer: sets are the easiest and most forgiving for beginners, transplants give the best balance of size and convenience, and seed is the cheapest and gives you the widest variety choice but takes the most time and skill. There’s no single “best” option — the right one depends on how much time you have before your growing season and how much control you want over variety selection.
Seeds vs Sets vs Transplants: Full Comparison
| Method | Time to Harvest | Cost | Variety Selection | Difficulty | Bolting Risk |
|---|---|---|---|---|---|
| Seed | Longest (150-180 days incl. indoor start) | Cheapest per plant | Widest — hundreds of varieties available | Hardest — needs an 8-10 week indoor head start | Lowest |
| Sets (small bulbs) | Shortest (90-120 days) | Moderate | Narrowest — usually just a few common varieties | Easiest — direct plant and go | Highest, especially with large sets |
| Transplants | Medium (100-120 days) | Highest per plant | Moderate — more choice than sets, less than seed | Easy — just plant at the right spacing | Low to moderate |
Why Sets Bolt More Often
Sets are small bulbs grown the previous season, and larger sets (over about 3/4 inch) have already experienced enough cold exposure to be primed to flower rather than just grow a bulb — which is why bolting is more common with sets than with seed or transplants. Choosing smaller sets (dime-sized) reduces this risk significantly, which is why experienced growers specifically seek out the smallest sets available rather than the largest.
Which Should You Choose?
- Choose sets if you’re new to growing onions, want the simplest possible method, or are planting later in the season than ideal for seed
- Choose transplants if you want a middle ground — easier than seed, more variety choice than sets, and you can find plug trays locally or by mail order
- Choose seed if you want a specific named variety not available as sets, want the lowest cost per plant at scale, or you’re set up to start seedlings indoors 8-10 weeks ahead
Many experienced growers use a mix: sets for an early, reliable crop and seed-started plants for specific storage varieties they want more control over.
FAQ
Do onions from sets taste different than from seed?
No meaningful flavor difference from the growing method itself — flavor comes mainly from the variety grown, not whether it started as a seed, set, or transplant.
Can I mix all three methods in the same garden?
Yes, and it’s a common strategy to stagger harvest times or hedge against one method underperforming in a given season.
Final Thoughts
There’s no universally “best” method — match it to your timeline and goals. Ready to start? See our full guides: growing from seed, growing from sets, or why bolting happens if that’s your main concern with sets.
How This Guide Was Checked
Based on extension planting-method comparisons and bolting-risk research by set size. Still deciding? Contact us with your timeline and we’ll help you choose.
Related Onion-Growing Guides
- Growing Onions From Seed: The Complete Step-by-Step Method
- Growing Onions From Sets: The Fastest Way From Garden to Harvest
- How Long Does It Take to Grow Onions? A Timeline by Method
See the full How to Grow Onions guide for the complete seed-to-harvest walkthrough.
