Allium cepa 'Stuttgarter Giant' is a traditional German yellow globe onion variety developed in the early 20th century around Stuttgart, producing large, flattened round bulbs with mild flavor and exceptional storage capability. The cultivar germinates readily without dormancy requirements and benefits from warm, consistently moist conditions; seeds germinate fastest at 20-25°C in darkness or low light and have no special stratification or scarification needs. This open-pollinated variety is widely valued for its reliability, hardiness in temperate climates, and excellent field performance when properly seeded.
Before sowing
No pre-treatment needed — sow directly.
Sowing
What to expect
Tips
Start seeds indoors 8-12 weeks before last frost in seed trays covered with plastic to maintain moisture; germination occurs in 7-14 days at optimal warm temperatures (20-25°C). Keep soil moderately moist but not waterlogged to prevent damping off. After germination, provide 12+ hours of bright light daily and maintain temperatures above 8°C at night to prevent bolting. Thin seedlings to 1 inch apart when 4 inches tall; transplant to individual containers (4+ inches deep) when they reach 3 true leaves for stronger root development. Harden off seedlings 4-6 weeks before planting outdoors in full sun on well-draining soil; avoid exposing seedlings to temperatures below 10°C for extended periods, as this triggers premature bolting rather than bulb formation.
Sources: RHS Plants Database, University Extension Services (Utah, Illinois), GrowVeg, SmartGardener, Folia Plant Database, Kokopelli Seeds, CropNerd, and peer-reviewed horticultural research on Allium cepa germination
