These very sweet onions are large, flattened globes of about 4'' in diameter and are ideal for slicing. Often grown for their vibrant color, their sweet flavor is lost during cooking, so it's preferable to consume them raw.
Onions take several weeks to mature, so it's best to start your seeds indoors in moist soil 2-3 months before the last expected frost in your region. When the green shoots start to fall over, cut them to about 3'' high to concentrate root growth. About 1 month before the last frost (when the soil temperature reaches at least 10°C or 50°F), transplant your seedlings outdoors at a depth of ½'' and a distance of 6'' in a sunny space. If you choose to sow directly in the garden, plant 3-4 seeds per hole and thin them as they grow.
Onions primarily need moisture to grow well, especially during the first few weeks. They struggle against weeds, so good mulching could help control moisture levels and weed proliferation.
Harvest when the leaves fall and become dry. Remove them from the soil, brush off the dirt, and let them dry in the sun for an entire week. If rain is in the forecast, bring them inside to a cool, airy place. When the skin is dry and crispy, trim the tops to 1'' and cut the roots. Store them for months in a cool, dry, and well-ventilated place.