Onion Seeds
There are three ways to grow an onion: from onion seeds, from seedlings and from sets, or bulbs. Growing onions from seeds is one of the most satisfying ways to grow this popular vegetable, because you start at the very beginning and watch your onion plant grow to maturity until their ready to be picked and enjoyed.
Onion seeds have to be purchased fresh each year, because the onion in a perennial plant, meaning it does not grow back year after year. It takes about 7 weeks for an onion seed to grow big enough for transplanting, so many people start their seeds inside and then move them outside after the last freeze passes through. If you’re lucky enough to live in a warmer, southern climate you can plant your seeds directly outside.
Step 1 – Get the Seeds
Most gardeners purchase their seeds from a nearby garden center or seed store. Local sellers usually carry varieties that grow well locally, so beginners and casual gardeners will want to use this simple and convenient source. There are also many wonderful seed selections from online gardening sources for anyone who wants to do a bit of research and likes a wider variety to choose from.
Step 2 – Plant the Seeds
Once you have the seeds, it’s time to get planting. Sow your onion seeds just ¼-inch deep in the seed container. Germination should begin within 7 to 14 days. Make sure your seedlings have plenty of light as they grow, and keep the leaves trimmed relatively short. It is not recommended that you thin out the young onion plants since their roots are so close to the surface of the soil.
Step 3 – Transplant the Seedlings into the Garden
Once the last frost of the season has passed – usually around mid-April – you can move your onion seedlings into their permanent home outside in the garden. Be sure the leaves are trimmed before transplanting to help support the root system. Onions enjoy full exposure to the sun and do best in rich, fertile soil. The onion is a versatile plant, though, and it can survive in most soil types and can even be planted in flower gardens, pots or boxes.
Step 4 – Harvest and Enjoy
Onions are ready to be picked when their tops begin to droop and fall over to the side. At this point, the onion is visible at the surface of the soil and you can tell when it has grown to the proper size for picking.
Onions are a home gardening favorite because they add flavor to thousands of different dishes and are good for you too. Another benefit is that they can be stored for a relatively long period of time. Keep them in a cool, dry place and your onions should last at least a few weeks. Hardy, tangy onions generally last a longer time than their sweeter counterparts.