Stuttgarter Riesen – a classic garden onion variety grown from seeds

🧅 Stuttgarter Riesen – a classic garden onion variety grown from seeds

Stuttgarter Riesen is one of the most popular garden onion varieties in Europe, cultivated for more than 100 years. These onions are firm, flat-round, with a strong flavour and excellent storage ability lasting all the way into spring. The variety is especially suitable for growing from seeds, as the plants are hardy, uniform, and rarely bolt. Suitable for both greenhouses and open gardens in Northern and Southern Europe.

📜 History of the Stuttgarter Riesen variety

Stuttgarter Riesen originated in the late 19th century in southern Germany, in the Stuttgart region. It was bred as a durable, uniform, long-storing table onion suitable for markets and farm production.
The name “Riesen” means “giant” in German, referring to its higher productivity and uniform bulbs. In the early 20th century, the variety appeared in European and American seed catalogues, and after World War II it became widely grown in Scandinavian and Soviet home gardens.
Today, Stuttgarter Riesen is considered a classic heritage variety, appreciated by both hobby gardeners and professional growers.

🌿 Variety characteristics

• Maturity: ~100–110 days
• Flat-round bulbs, 80–150 g
• Firm white flesh, golden-brown skin
• Strong, aromatic flavour
• Excellent storage quality
• Suitable for greenhouses and open gardens
• Especially good for growing from seeds

🍽 Flavour and culinary use

• Strong, pronounced onion flavour
• Firm, dense flesh that keeps quality during storage
• Great for frying, sautéing, pickling, and winter storage
• A universal variety for everyday cooking

🌱 Sowing and seedling cultivation of Stuttgarter Riesen

Sowing:

Northern Europe: January–February
Southern Europe: late January–mid-February

• Sow seeds 1 cm deep in light, airy substrate
• Germination requires +18…+22 °C and 14–16 h of light
• Provide sufficient light to prevent leggy seedlings
• Water moderately, avoid overwatering
• Onion seedlings are not usually pricked out, so sow seeds thinly or in rows from the start

Seedling cultivation:

• Seedlings grow best at +14…+18 °C
• Harden seedlings before planting outdoors
• Plant at 8–10 cm spacing, 25–30 cm row spacing
• The neck must remain close to the surface — do not plant deeply
• Water gently after planting

🌞 Growing in the garden and greenhouse

🏡 Northern Europe – best in open garden beds or raised beds

• Stable moisture conditions
• Larger and more uniform bulbs
• Lower risk of rot compared to greenhouses

☀️ Southern Europe – ideal in open gardens

• Strong sun develops aromatic, firm flesh
• Mulching and drip irrigation recommended
• Performs better outdoors than in a greenhouse

🍽 What influences the flavour and quality of onions?

🌞 Sunlight

• Produces firmer, less watery bulbs
• Shady areas result in smaller and milder onions

💧 Moisture

• Even watering at the start of the season
• Reduce watering in July for proper bulb ripening
• Overwatering increases neck-rot risk

🌡 Temperature

• Ideal +18…+26 °C
• Heat above +30 °C reduces bulb size

🌱 Fertilising

• Potassium promotes firm bulb formation
• Calcium strengthens the neck and improves storage
• Use nitrogen sparingly — excess promotes leaf growth instead of bulb growth
• Organic fertiliser is especially suitable for garden cultivation

🚫 Companion plants to avoid

• Beans, runner beans, peas
• Potatoes
• Garlic, leeks, shallots, chives
• Cabbages and other brassicas
• Beets
• Cucumbers, courgettes

(Best companions: carrots, lettuce, spinach, strawberries.)

❗ Common mistakes when growing Stuttgarter Riesen from seeds

• Sowing too late — seeds must be sown in January–February
• Insufficient light for seedlings
• Overwatering
• Planting too deeply
• Excess nitrogen fertiliser
• Watering late in the season
• Harvesting in wet weather
• Not following crop rotation in the garden

🎁 Seeds per pack: 10 pcs
Author: Heart Garden Studio