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Allium cepa Spanish Yellow Sweet Onion

Allium cepa Spanish Yellow Sweet Onion is a classic, long-day variety treasured for its massive, globe-shaped bulbs and exceptionally mild, sweet flavor. Growing to about 12 to 18 inches tall with bulbs often reaching softball size (4 to 6 inches in diameter), this variety is a favorite for home vegetable gardens and market growers where impressive size and versatility are key. Unlike pungent storage onions, the Spanish Yellow Sweet offers a delicate texture and sugary profile that makes it versatile for both raw and cooked applications, maturing in late summer for a bountiful harvest.

 

Culinary and Practical Uses

  • The jumbo, thick-walled rings are the industry standard for making fried onion rings and French onion soup due to their high sugar content and mild taste.
  • Excellent for caramelizing or roasting, where the natural sugars brown beautifully, creating a rich, savory-sweet flavor perfect for topping burgers and steaks.
  • While milder than storage types, it has better keeping qualities than many other sweet onions, storing reliably for several months in cool, dry conditions.

 

Characteristics

  • Foliage: Upright, tubular, blue-green leaves (scapes) that are vigorous and sturdy; essential for fueling the rapid expansion of the large bulbs.
  • Growth Habit: Biennial grown as an annual; produces large, uniform, golden-skinned bulbs with crisp, white flesh that lacks the sharp "bite" of standard yellow onions.
  • Flowers: Typically harvested before blooming, but if left to overwinter, it produces tall stalks topped with spherical, white flower umbels attractive to pollinators.
  • Seeds: Harvested after flower heads dry; the small, angular black seeds are vigorous and ideal for starting indoors early to maximize the growing season.

 

Growing Requirements

  • Sun: Thrives in full sun; requires long days (14 to 16 hours of sunlight) to trigger bulb formation, making it ideal for Northern and Transition zones.
  • Soil: Adapts to most soil types but thrives in loose, fertile, well-draining loam rich in organic matter to allow for easy bulb expansion.
  • Water: Requires moderate, consistent watering; keeping soil evenly moist is critical for producing the largest, sweetest bulbs without splitting.
  • Spacing: Plant transplants 4 to 6 inches apart in rows 12 to 18 inches apart to accommodate the large potential size of the mature onions.
  • Maintenance: Keep beds strictly weed-free as onions compete poorly; stop watering when tops fall over to allow bulbs to cure before harvesting.

 

Shipping Info

Spanish Yellow Sweet Onion seeds ship as fresh, high-quality, viable seeds that are carefully packaged for stability and protection from damage during transit. Prompt shipping supports reliable germination and seasonally appropriate planting.

Growing Zones

3a - 9b
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Low Temperature

20°F

High Temperature

90°F

Fragrant

Yes

Polinator Required

No

Polinator Friendly

Yes

Flower Color

Blue Bronze Green White

Growth Rate

Moderate

Soil

Loose, fertile, well-draining soil

Moisture

Moderate

Sun Exposure

Full Sun

Mature Spread

4 - 6 inches

Mature Height

12 - 18 inches

Bloom Period

Summer

Pruning Time

Early Spring

Pet Safe

No

Perennial / Annual

Annual

Evergreen / Deciduous

Deciduous

Blossomdale
Blossomdale
Blossomdale

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