Onion Seeds,
Ishikura Bunching

Start seeds indoors three months before the last expected frost date in spring. Onions begin slowly, so this early start allows for adequate growth before transplanting. Transplant acclimated, stocky seedlings into the garden 4-6 weeks before the last frost of spring, as onions can tolerate light frosts. If you’re not sure how to find your area's day length or first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Sow seeds 1/4 inch deep in rows or clusters, keeping the soil temperature at around 60 F. Thin seedlings to 4-6 inches apart, or plant more densely if harvesting as young scallions. Keep rows 12 inches apart for proper spacing.

Feed with a balanced fertilizer every 3-4 weeks for the best growth. Keep soil consistently moist but not waterlogged. Weed regularly to minimize competition, as bunching onions do not compete well with other plants. Harvest the green stalks as needed, cutting them at the base to encourage regrowth.

• Onions will cross with other onions, and occasionally they will cross with scallion types like Welsh onions and Hi Shi Ko bunching onions. Onions will never cross with leeks, chives or garlic.
• If you are growing types that will cross, try to isolate varieties by at least several hundred feet or ideally up to one mile.
• Onions are a biennial seed crop, so you will need to overwinter your first-year roots, ideally by digging them up and storing them for the winter. Replant in early spring, and allow onions to shoot up spikes of purple flowers.
• Let seeds become dry on the plants. Pick seeds when they are hard and dark black, then bring them indoors to finish drying.
• Once dry, separate the seeds from the husks or leave them on and plant them husks and all.