Allium cepa 'Rouge Foncé de Hollande' is a heirloom red onion variety originating from the Netherlands, prized for its sweet, full-bodied flavor and deep crimson color with distinct rings. This biennial bulbous plant requires consistent moisture and moderate temperatures for seed germination, which typically occurs within 7-14 days when maintained at optimal soil conditions.
Before sowing
No pre-treatment needed — sow directly.
Sowing
What to expect
Tips
Sow seeds indoors 8-10 weeks before last frost. Cover seeds lightly with 1/8 to 1/4 inch of soil or seed-starting medium. Maintain soil moisture throughout germination using a spray bottle to avoid waterlogging. Once seedlings emerge, provide 12-16 hours of bright light daily and keep growing temperature at 55-65°F to prevent spindly growth. Thin seedlings to one per cell after germination. Transplant when seedlings reach 3-4 inches tall. Avoid temperatures below 50°F for extended periods to prevent bolting. Onion seeds have short viability; store at temperatures below 40°F for optimal retention up to three years. Do not fertilize until transplanting; onions prefer well-drained fertile soil rich in organic matter.
Sources: Grow Veg, Utah State University Extension, Johnny's Selected Seeds, High Mowing Seeds, West Coast Seeds, Seeds Savers Organization, IDSeed Identification Guide
