VegetableOnion
Texas Grano 502 Onion
Texas Grano 502 is a short-day onion variety developed by Texas A&M in 1944, engineered specifically for southern growing conditions where mild winters allow early fall planting. This heirloom produces large, golden-skinned bulbs measuring 3 to 4 inches across with a notably mild, sweet flavor that rivals the famous Vidalia onions. Maturing in 110 to 119 days, it thrives in zones 2 through 9 and stores reliably for 2 to 3 months when properly hung, making it both a fresh-eating favorite and a practical keeper for the pantry.
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
This onion was purpose-built for southern gardens where traditional long-day varieties struggle. Texas A&M researchers spent decades perfecting it to deliver both the sweetness home cooks crave and the storage capacity serious gardeners need. Its golden skin conceals a mild interior that softens beautifully when cooked, yet remains crisp and pleasant when sliced fresh, giving it unusual range across the kitchen.
Common Uses
Fresh eating is where Texas Grano 502 shines; its mild sweetness and tender bite make it excellent for slicing into salads, salsas, and sandwich toppings. The bulbs cook down beautifully in caramelized preparations, French onion soup, and creamed dishes, where their natural sugars concentrate into deep, mellow flavors. For those who find standard storage onions too sharp, this variety bridges the gap between fresh-eating and keeping types, letting you enjoy milder onions throughout the winter months when stored properly.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Start Indoors
Start seeds indoors 8 to 10 weeks before your intended transplant date, keeping soil at 50 to 70 degrees Fahrenheit until germination. Maintain bright light and moderate moisture; allow seedlings to develop a few true leaves before hardening off.
Transplant Outdoors
In the southern United States, transplant seedlings outdoors in early fall (August through September) for spring and early summer harvest. In northern zones, transplant in early spring after the last frost. Harden off seedlings over 7 to 10 days before moving them outside. Space plants 3 inches apart with rows 15 inches wide, burying them slightly deeper than they grew indoors to encourage strong root establishment.
Direct Sow
Direct sow seeds outdoors in early fall in southern regions, planting at a depth of 1/4 inch and thinning seedlings to 3 inches apart once they develop their first true leaves.
Harvesting
Harvest when the tops begin to brown and fall over, typically 110 to 119 days after planting. Gently lift bulbs from the soil and allow them to cure in a warm, dry, well-ventilated space for 2 to 3 weeks before storing. You'll know they're ready when the outer papery skin is completely dry and the neck has sealed tightly. Cut or twist off the dried tops once curing is complete, leaving about 1 inch of stem attached.
Growing Calendar
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Companion Planting
Pests & Diseases
Ecology & Traits
Edible
Scientific Classification
Allium cepa
Family
Amaryllidaceae
Genus
Allium
Native Status
L48 (I)
History & Origin
“Texas Grano 502 emerged from Texas A&M University's breeding program in 1944, born from the challenge of creating an onion suited to the South's unique growing season. Rather than importing varieties bred for northern climates, researchers developed a short-day cultivar that bulbs up as days shorten in autumn, allowing gardeners across the southern United States to harvest in spring and early summer. This practical solution to a regional problem became an heirloom in its own right, passed down through generations of southern gardeners who recognized its reliability and flavor.”