VegetableOnion
White Grano Onion
White Grano Onion is a short-day bulbing variety that thrives in southern and western gardens, delivering reliable harvests in 100-109 days. This open-pollinated heirloom grows 14-24 inches tall and handles cold well, making it a dependable producer across hardiness zones 2-9. Unlike longer-day varieties, it resists bolting and performs steadily as an annual crop, whether you're planting in garden beds, raised boxes, or containers.
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
Moderate
Hover over chart points for details
Highlights
This short-day variety was bred specifically for the South and West, where it remains a heavily cultivated commercial crop for good reason. Its cold tolerance and resistance to premature bolting set it apart from typical onion varieties, giving you a slower, steadier path to a full harvest. The open-pollinated genetics mean you can save seeds year after year, connecting you to a continuous chain of gardeners who've relied on this variety.
Common Uses
These onions are versatile kitchen staples suited to any application where sweet, mild onions shine. Slice them fresh into salads, caramelize them for soups and stews, roast them whole, or pickle them for long-term storage. Their mild character and reliable quality also make them excellent for grilling and for any recipe where you want onion flavor without harsh bite.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Start Indoors
Start seeds indoors 8-10 weeks before your last spring frost in seed trays with warm soil (70°F ideal). Keep soil consistently moist and provide bright light. Transplant seedlings to the garden once they reach 4-6 inches tall and soil has warmed.
Transplant Outdoors
Transplant seedlings outdoors after hardening off for 7-10 days. Move to the garden after the last frost date when soil temperature reaches at least 50°F. Space 3 inches apart in rows 15 inches apart. Plant at the same depth they grew indoors, and water gently to settle soil around roots.
Direct Sow
Direct sow seeds in early spring as soon as soil can be worked. Press seeds lightly into soil and keep the top 1/4 inch consistently moist until seedlings emerge in 7-14 days.
Harvesting
Harvest White Grano Onions in 100-109 days when bulbs have fully formed and the tops begin to brown and fall over naturally. This toppling signals the bulb is mature and ready to lift. Gently dig bulbs and allow them to cure in a warm, dry location with good air circulation for 2-3 weeks before storing, which hardens the papery outer skin and extends 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
“White Grano Onions represent a significant development in short-day onion breeding, engineered to thrive in the specific climate conditions of southern and western United States agriculture. The variety emerged from breeding work focused on creating bulbing onions adapted to these regions' growing seasons, where traditional long-day varieties struggled to form proper bulbs. Maintained as an open-pollinated heirloom, it carries the stability and reliability that comes from decades of farmer selection and seed saving across Texas, the Southwest, and beyond.”