Stuttgarter Onion is a long-day heirloom that delivers medium-large, golden-yellow bulbs with a pungent flavor that improves in storage. Hardy from zones 2 to 9, this variety matures in 80 to 100 days and produces slightly flattened globes with white flesh inside. It's one of the best keepers in the onion world, meaning you can harvest in fall and eat your way through winter and into spring without losing quality.
4
Full Sun
Moderate
2-9
14in H x ?in W
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Moderate
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Golden onions with bronze skin and white flesh inside, these bulbs develop a pungent, savory character that deepens as they cure and store. Stuttgarter is legendary for its keeping ability, holding its flavor and texture through months of storage without sprouting or deteriorating. The variety thrives in cooler climates where many other long-day onions struggle, making it especially valuable for northern gardens.
Stuttgarter Onions excel in slow-cooked dishes where their pungent character mellows and deepens, from caramelized onions to hearty stews and soups. Their firm texture and long storage life make them ideal for winter larders, where they provide onion flavor from autumn through early spring. The mild sweetness that emerges during cooking suits them to gratins, roasted vegetable preparations, and traditional European cuisine.
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Start seeds indoors 6 to 8 weeks before your last spring frost. Keep soil at 45 to 80 degrees Fahrenheit for germination, which typically occurs within 7 to 14 days. Seedlings should be hardened off gradually before transplanting outdoors.
Transplant seedlings outdoors after the danger of heavy frost has passed and soil can be worked, typically 4 to 6 weeks before the last frost date. Plant at the same depth they grew indoors, spacing them 4 to 6 inches apart with rows 15 inches wide. Water gently after transplanting to settle soil.
Direct sow seeds outdoors in early spring as soon as soil can be worked. Sow at a depth of 1/4 inch and thin seedlings to 4 to 6 inches apart once they have developed 2 to 3 true leaves.
Harvest Stuttgarter Onions after 80 to 100 days when the tops begin to yellow and fall over naturally. This toppling indicates the bulb has finished growing and begun moving nutrients back into storage. Gently lift bulbs from the soil and cure them in a warm, well-ventilated area away from rain for 2 to 3 weeks until the outer skins papery and necks completely dry down before storing.
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“Stuttgarter Onion takes its name from Stuttgart, Germany, where it was developed and refined over generations. This heirloom cultivar represents the accumulated knowledge of European onion breeders who selected for cold hardiness, reliable bulb formation, and exceptional storage longevity. The variety has been passed down through seed-saving traditions and is now preserved by heirloom seed companies, connecting modern gardeners to centuries of European vegetable cultivation.”