While it’s easy to purchase onions at the grocery store in winter or the farmers’ market in summer, there’s something special about growing your own varieties. Onions are not just the round yellow or red balls we normally find. They come in a wide range of shapes and sizes, each with particular characteristics that makes it unique. If you start onions from seed indoors now, in mid February, you’ll be able to select the best varieties for your needs and grow as many as you like inexpensively in your garden. Here’s how to get started:
Varieties: Depending on where you live, you will select short-day, long-day, or intermediate-day onion varieties. Long-day varieties, such as ‘Copra’, produce bulbs in response to the long days of early summer. Short-day varieties, such as ‘Texas Grano’, produce bulbs in response to the short days of spring. Intermediate-day onions, such as ‘Candy’, are not dependent on day length to form bulbs. This time of year (mid-February), plant long-day or intermediate-day onions for spring planting and summer harvest. Short-day onions should be planted in fall in mild-winter areas.
Type of Onion: Onions are generally categorized as either storage or sweet. Storage onion varieties, such as First Edition, tend to be smaller in size but will last six to eight months in storage in winter indoors. Sweet varieties, such as Walla Walla, can be large but will only last a few weeks in storage.
Starting Seed: Start onion seed eight to ten weeks before the last frost date in your area. Sprinkle the seed in rows in seed trays filled with moistened potting soil. To enhance seed germination, keep the trays covered with clear plastic and keep them warm.
Growing: Once the onions germinate, place the trays under grow lights turned on for fourteen hours a day. Thin the seedlings to one quarter inch apart. Keep the soil evenly moist, and fertilize every few weeks with an organic liquid plant food.
Hardening Off: A week or so before planting outside, harden off your seedlings, getting them used to the cold air temperatures and wind.