VegetableOnion
Eclipse L303 Onion
Eclipse L303 is a short-day onion that produces crisp, medium-size white bulbs with a mild flavor that works beautifully in everything from fresh salads to slow-simmered soups and stews. This open-pollinated, heirloom variety thrives in Southern climates but can be grown in longer-day regions as well, reaching maturity in 110 to 119 days. Hardy across zones 2 through 9, it adapts readily to greenhouses, garden beds, and raised beds, delivering reliable harvests whether you're a seasoned gardener or just starting out.
Photo © True Leaf Market
Growing Conditions
USDA Zone
2-9
Sunlight
Full Sun
Water
Moderate
Soil
Well-drained, Fertile Loam, Moderately Rich
Growth Stats
24 in
Height
Spacing
3
Plant Profile
Sunlight
Full Sun
Water
Moderate
Zones
2-9
Size
24in H x ?in W
Growth
—
Care
High
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Highlights
Eclipse L303 produces distinctive white onions with a crisp texture and genuinely mild flavor that doesn't overpower delicate dishes. It's an open-pollinated heirloom bred specifically for warm-climate growing, yet flexible enough to succeed in colder zones too. The variety thrives in diverse growing environments, from traditional garden plots to raised beds and even greenhouse conditions, making it one of the most adaptable onions you can grow.
Common Uses
Eclipse L303 onions excel in fresh applications where their mild character shines without overwhelming the palate. Slice them thin for crisp, sweet additions to salads and burger toppings, or use them whole in roasting and caramelizing where their gentle flavor deepens into something rich and satisfying. They're equally at home in the soup pot and stew pot, contributing body and subtle sweetness to broth-based dishes where a milder onion won't compete with other ingredients.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Harvesting
Harvest Eclipse L303 onions at 110 to 119 days after planting, or when the foliage yellows and begins to fall over naturally. This leaf-down stage signals that the onion has finished bulking and is ready to lift from the soil. Gently dig around each bulb and pull it up, being careful not to bruise the tender skin. If desired, cure the onions in a warm, dry location with good air circulation for a week or two to harden off the papery outer layers and improve storage life.
Growing Calendar
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Companion Planting
Ecology & Traits
Edible
Scientific Classification
Allium cepa
Family
Amaryllidaceae
Genus
Allium
Native Status
L48 (I)
History & Origin
“Eclipse L303 emerges from the tradition of open-pollinated, heirloom bulbing onions developed for Southern agriculture. As a short-day variety, it was specifically selected and refined for growing regions where day length is shorter during the critical bulbing stage, reflecting generations of regional agricultural knowledge and seed selection. The variety represents the kind of cultivar that traveled through seed catalogs and home gardens, preserved by gardeners who valued its reliable performance and mild flavor.”