The biggest mistake new vegetable gardeners make is starting onions from seed indoors under lights, only to watch the fragile green tops stretch, flop, and fail by transplant day. Against that frustration, plump, dormant onion sets offer a head start measured in weeks of growth and a bulb that actually sizes up before the summer solstice triggers the clock. Choosing the right set—and the right variety—separates a pantry full of storage onions from a bench full of regret.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I’ve spent years digging into germination data, bulb maturity tables, and soil temperature benchmarks to pin down which sets give home growers the highest success rate for the least effort.
This guide cuts through the packaging noise to compare head count, bulb size consistency, variety mix, and regional day-length suitability so you can confidently pick the best gardening onion sets for your spring bed, raised row, or patio container.
How To Choose The Best Gardеning Onion Sets
Onion sets are dormant, immature bulbs that give you a massive head start over seed, but they also force you to make decisions about variety and harvest timing before the first bulb goes into the soil. Ignoring a few key variables—especially the day-length group—can turn a whole bed of sets into a bed of skinny scallions that never fatten up.
Day‑Length Classification Is Non‑Negotiable
Every onion variety responds to a specific number of daylight hours before it stops making leaves and starts swelling the bulb. Long-day sets need 14–16 hours of daylight and perform best north of the 37th parallel. Short-day sets start bulbing at 10–12 hours and are built for southern gardens. Intermediate (day-neutral) sets work across most of the continental US. A mismatched set will either bulb too early and stay small or never bulb at all.
Set Diameter Dictates Outcome
Sets smaller than a dime produce the largest storage bulbs at harvest because they are less prone to bolting (premature flowering). Large sets—nickel-sized and up—are more likely to bolt, but they yield fantastic early green onions or scallions in just three to four weeks. Decide whether you want spring greens or fall storage bulbs, then pick the set size accordingly.
Freshness and Handling
Sets that arrive soft, sprouted with elongated tops, or showing any mold ring around the neck have already spent too much time in warm storage. Look for firm, papery bulbs with no visible green shoots. Reputable sellers store their stock at near-freezing temperatures through winter to keep the bulbs dormant until you plant them.
Quick Comparison
On smaller screens, swipe sideways to see the full table.
| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Mixed Red, White, Yellow (Stargazer) | Premium Mix | Multi-color harvest & storage | 1 lb (80–100 sets) 3-color intermediate/long/short | Amazon |
| TomorrowSeeds 3-Color Mix | Mid-Range Mix | Fresh eating plus starting a mix | 1 lb red/white/yellow intermediate-day | Amazon |
| Cool Beans N Sprouts Yellow 100 ct | Premium Bulk | Large dry bulb production | 100 count yellow sets | Amazon |
| Yellow Onion Starter Sets (Country Creek) | Budget Bulk | High-volume green onion beds | 100 count standard yellow sets | Amazon |
| Stuttgarter Yellow (Stargazer) | Budget Focused | Classic storage onion benchmark | 50–60 bulbs US-grown Stuttgarter | Amazon |
In‑Depth Reviews
1. Mixed Red, White, and Yellow Onion Sets 1 lb (Stargazer Perennials)
Stargazer Perennials provides a full pound of hand-sorted sets that typically yield 80 to 100 bulbs of mixed red, white, and yellow onions. The inclusion of intermediate, day-neutral, and long-day varieties means this bag works across a wide band of latitudes, though growers in the Deep South should still verify short-day representation. The sets arrive with a printed tip sheet that covers planting depth, spacing, and the 14-day curing process for storage onions.
The three-color mix creates an immediate visual payoff in the garden and a longer harvest window: you can pull the earliest bulbing reds as fresh onions while the yellows continue sizing up for fall storage. The bulbs are non-GMO and grown in the USA. The main limitation is that the random mix of day-length types means a percentage of the order may not perform optimally in your specific zone if you are at an extreme northern or southern latitude.
Owners consistently report that these sets arrive firm, tightly dormant, and free of rot or premature sprouting—critical for growers who want to plant immediately without culling soft bulbs. The quantity is generous enough for a 50-foot row or several large raised beds.
What works
- Three color types (red, white, yellow) for culinary variety
- Hand-sorted, firm sets with low bolting risk
What doesn’t
- Day-length types are mixed, not labeled per bulb
- Cannot ship to Washington or Idaho
2. TomorrowSeeds 3 Colors Mix Onion Sets (1 Pound)
TomorrowSeeds packs a full pound of mixed red, white, and yellow sets described as intermediate-day, which positions them as day-neutral and therefore adaptable across most mainland US zones (USDA hardiness zone 2 through warmer climates). The sets are non-GMO and stored cold to maintain dormancy. The mix targets the home cook who wants a constant supply of green onions early followed by mature bulbs later.
The stated summer bloom period indicates these are programmed to bulb once daylight exceeds a moderate threshold, making them safer for central and northern gardens than a strict short-day variety. The sandy-soil preference noted in the specs aligns with standard onion-growing advice: loose, well-draining ground prevents the bulbs from sitting in moisture that invites rot. The main drawback is that because the three colors are mixed, you cannot plant them in separate uniform rows unless you hand-sort them first.
Growers note that the sets are generally clean and un-sprouted upon arrival, though the number of sets per bag varies depending on bulb size—16 ounces of large sets yields fewer individual plants than 16 ounces of small dime-sized ones.
What works
- Intermediate-day classification suits most growing regions
- Cold-stored to reduce premature sprouting before planting
What doesn’t
- Colors are pre-mixed, preventing tidy row separation
- Exact count not guaranteed due to size variation
3. Cool Beans N Sprouts Yellow Onion Sets (100 Count)
Jacobs Ladder Ent’s Cool Beans N Sprouts brand delivers a straight hundred-count of yellow onion sets—no mixed colors, no day-length ambiguity, just a single-variety bag for the grower who wants a uniform harvest. Yellow onions are the gold standard for long-term storage because of their high pungency and thick, papery skins, so this bag is built for the pantry-focused gardener who wants a single large planting of storage bulbs.
The expected planting window spans spring and fall, which gives flexibility in mild-winter zones where a fall planting can overwinter for an early summer harvest. Full sun and moderate watering are the only requirements. The 100-count bag covers approximately 50 to 75 linear feet of row when spaced four to six inches apart. The main limitation is the absence of variety labeling—without knowing the specific cultivar, you cannot precisely match day-length requirements to your latitude.
Feedback from growers suggests the bulbs arrive dry and firm, with very few soft or rotten units in the bag. If you prioritize a simple, large planting of reliable yellow storage onions without the complexity of a mixed bag, this delivers.
What works
- High count (100) for large beds or multiple rows
- Single-variety yellow means uniform bulb size at harvest
What doesn’t
- No specific day-length classification stated on listing
- Count may include varying bulb diameters
4. Yellow Onion Starter Sets – 100 Count (Country Creek LLC)
Country Creek LLC’s 100-count yellow onion starter sets are positioned as an entry-level option for gardeners who want high volume without a premium price tag. The sets are standard yellow onions suitable for both early green table onions and full-size dry bulbs if left to mature. The product dimensions (9 x 4 x 12 inches) indicate a bulk-style bag that fits easily into a larger shipping box.
The dual-use promise is the standout feature: you can harvest half the row as scallion-size greens within three to four weeks, then let the remaining sets space out and bulb up for storage. This makes the bag particularly efficient for small-space growers who want continuous harvests from a single planting. The sets are competitively priced for the count, but the minimal spec sheet means you will need to rely on standard cultural practices for spacing, watering, and curing rather than cultivar-specific advice.
Anecdotal grower reports note that the sets are generally healthy, though the bag may occasionally include a few oversized bulbs that are more prone to bolting. Sorting by size before planting—using the dime test for storage and the nickel test for greens—mitigates this risk.
What works
- High set count (100) maximises planting area per bag
- Suitable for both spring greens and full storage bulbs
What doesn’t
- Minimal product description means limited day-length info
- Occasional oversized sets increase bolting risk
5. Stuttgarter Yellow Onion Sets (Stargazer Perennials, 50–60 Count)
Stargazer Perennials’ 8-ounce bag of Stuttgarter yellow onion sets is a focused offering for the grower who wants a proven storage-onion cultivar. Stuttgarter is a long-day variety that produces large, pungent bulbs with excellent keeping quality through winter. The 50–60 count is the smallest of the options reviewed, making it a good starter pack for a single raised bed or a row of roughly 25 feet.
The sets are grown and packaged in the USA, which reduces shipping stress compared to overseas imports. Stuttgarter’s reputation for consistent bulbing under long-day conditions above the 37th parallel makes this a reliable choice for northern-tier gardeners. The drawback is that the pack size is limited—gardeners with significant row space will need to buy multiple bags—and long-day sets planted south of the 35th parallel will not bulb properly.
Feedback from northern growers highlights the sets’ high germination rate and the firm, tight bulb formation at harvest. If you garden in the northern half of the US and want a single proven variety for winter storage without mixing colors, this is a targeted purchase.
What works
- Proven Stuttgarter cultivar for cold storage
- USA-grown and packaged, reducing shipping damage
What doesn’t
- Long-day only: unsuitable for southern gardens
- Relatively small count for larger planting areas
Hardware & Specs Guide
Day‑Length Group
Long-day sets need 14–16 hours of daylight and thrive north of the 37th parallel (roughly a line through San Francisco, southern Colorado, and Richmond, Virginia). Short-day sets bulb at 10–12 hours and work best south of the 35th parallel. Intermediate (day-neutral) sets adapt to most latitudes. Check the product listing for the specific group before buying.
Set Size vs. Harvest Goal
Dime-sized sets (under 1/2 inch diameter) produce the largest storage bulbs because they resist bolting. Nickel-sized sets (3/4 inch) yield faster spring greens but may bolt before forming a full dry bulb. The bag label seldom states diameter, so inspect a sample after arrival and sort by size before planting.
FAQ
Can I plant onion sets in containers?
How do I know if my onion sets are still dormant when they arrive?
Should I soak onion sets before planting?
Final Thoughts: The Verdict
For most gardeners, the best gardening onion sets winner is the Mixed Red, White, and Yellow set from Stargazer Perennials because it delivers a full pound of three-color, hand-sorted bulbs with a day-length mix that adapts to a wide range of growing zones. If you want a straightforward bulk planting of one variety for storage onions, grab the Cool Beans N Sprouts 100-count yellow set. And for a focused, northern-tier storage onion with a proven track record, nothing beats the Stuttgarter Yellow set from Stargazer Perennials.