Allium fistulosum, commonly known as Welsh onion or bunching onion, is a non-bulbing, perennial allium species native to China and widely cultivated across Asia, Europe, and North America. Unlike regular bulbing onions, this species produces long, hollow green stems prized for culinary use. Seeds germinate readily over a wide temperature range, making them an excellent choice for both indoor and direct outdoor sowing.
Before sowing
No pre-treatment needed — sow directly.
Sowing
What to expect
Tips
Sow seeds at 1/4 inch deep and tamp soil firmly; provide consistent moisture without waterlogging during germination. Germination is fastest at room temperature (65-75°F/18-23°C) with emergence in 7-10 days. Seeds do not require light and are indifferent to light conditions. Avoid humidity domes and provide good air circulation to prevent fungal diseases. For better germination rates, do not use heat mats as this actually reduces germination success. Bottom watering is preferred over overhead watering. Apply light mulch after germination to retain moisture and regulate soil temperature.
Sources: Oregon State University College of Agricultural Sciences, Plants For A Future, Missouri Botanical Garden, Academic journals on Allium physiology, Hudson Valley Seed Company, Multiple seed producers and gardening resources
