Save your own onion seeds for next season, it’s easy and a great way to grow onions adapted to your garden! Onions are biennial, they grow bulbs the first year and flowers (with seeds) the next. By leaving a few onions in the ground over winter, they’ll bloom in spring and produce seeds for you to harvest. How to collect onion seeds: 1. Leave a few onions in the ground over winter. 2. Wait for flower heads to bloom and mature. 3. Let heads dry, brown and crispy means seeds are ready. 4. Collect