Sweet Onion
Yellow Granex is a specialized short-day onion hybrid developed specifically for southern growers, where its photoperiodic nature allows it to form proper bulbs during the region's shorter winter days. This F1 hybrid matures in 140-150 days from transplants, producing sweet, mild bulbs that have made it a cornerstone of southern onion production. Unlike long-day varieties that struggle in the South, Yellow Granex thrives in regions below 36° latitude, timing its bulb formation perfectly with the 10-12 hour days of southern winters.
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High
3-11
?in H x ?in W
Biennial (Grown As Annual)
Moderate
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This short-day specialist represents the perfect marriage of science and regional adaptation, engineered to work exclusively with the photoperiodic conditions of the American South. Yellow Granex transforms from transplant to mature bulb over nearly five months, developing its characteristic mild sweetness as it responds to the shorter day lengths that trigger bulbing. Its hybrid vigor and regional specificity make it an essential variety for southern gardeners who have struggled with northern onion varieties that simply won't bulb properly in their climate.
Yellow Granex produces mild, sweet bulbs perfect for fresh eating, cooking, and storage applications. The variety's gentle flavor profile makes it excellent for dishes where onion presence is desired without overwhelming heat, while its good storage characteristics allow southern growers to enjoy home-grown onions well into the storage season.
In long and intermediate-day areas, sow seeds indoors 6-8 weeks before the last frost date. Plant one seed per cell in 128-cell trays, covering with 1/4 inch of soil. Alternatively, sow 10-12 seeds in 4-6 inch pots for later separation.
Transplant seedlings 4 inches apart in rows 12-18 inches apart. If tops have grown unruly or exceed 5 inches, clip them back to 3-5 inches at transplant time. When planting pot-grown seedlings, carefully separate them and place in shallow trenches, filling soil around them and watering in well.
Monitor for bulb maturity as tops begin to fall over naturally. When about half the tops have fallen, push over the remaining green tops and wait about one week before harvesting. Cure harvested bulbs in a warm, shaded, well-ventilated location at 75-80°F until outer skins and necks are completely dry, typically 2-4 weeks.
Trim tops to 5 inches if they become unruly before transplanting, and clip back to 3 inches if pot-grown seedlings have grown too tall before planting out.
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