Red Amposta is a classic European bulb onion that matures in 115 days and produces deep red bulbs suited to zones 3 through 10. This variety rewards early starting with larger, more uniform bulbs, making it a reliable choice for gardeners who want both storage quality and the deep color that comes naturally from its heritage genetics. Plant it in full sun with moderate water, and you'll harvest substantial red onions ready for long-term storage by late summer.
Full Sun
Moderate
3-10
?in H x ?in W
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Moderate
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Red Amposta delivers the deep crimson color and reliable bulb formation that European growers have trusted for generations. Starting seeds indoors 10 to 12 weeks before your last frost date and transplanting early produces noticeably larger bulbs than late starts. The variety thrives across a wide hardiness range and stores exceptionally well once cured, making it as practical for the root cellar as it is beautiful in the kitchen.
Red Amposta bulbs are primarily used fresh in cooking, sliced raw into salads where their color adds visual impact, roasted whole or in wedges, caramelized for deep umami flavors, and stored for winter use. The deep red skin and layers make them excellent for long-term storage, allowing gardeners to enjoy them months after harvest.
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Sow seeds indoors 10 to 12 weeks before your average last frost date at a depth of 1/4 inch. Maintain soil temperature between 60°F and 85°F for optimal germination and growth. Transplant seedlings outdoors 4 to 6 weeks before your last frost date for the best bulb size.
Transplant seedlings outdoors 4 to 6 weeks before your average last frost date, once soil can be worked and has warmed to at least 45°F. Space plants 12 inches apart in rows 12 inches apart. Earlier transplanting produces noticeably larger bulbs.
Sow directly outside 4 to 6 weeks before your average last frost date, as soon as soil can be worked and reaches 45°F. Direct sowing produces smaller bulbs than transplanting, so indoor starting is recommended.
Harvest Red Amposta bulbs after approximately 115 days when the foliage begins to yellow and fall over naturally. Pull bulbs from the ground and allow them to cure in a warm, dry location for 2 to 3 weeks before storage, which develops the papery outer skin and deepens storage life.
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