Onions are a favorite for many gardeners. They’re easy to grow and best of all, delicious to eat. They are also a very versatile plant that requires little fuss. You can grow them in containers, in raised beds, directly in the ground, or just tuck them into the edges and spare corners in your garden beds.
Onions can be grown in several ways.
You can grow them from transplants, from sets, or from seeds. Transplants are sometimes called “bunches” of onons. These bunches are groups of already started seedlings and are usually available at your local nursery or from mail order. Onion bulbs are another option. These onion bulbs are often called “sets” of onions. This method makes for easy planting and early harvest, which many gardeners love.
Growing onions from seed is probably the most lengthy process for growing onions at home, but it can be the most rewarding.Growing onion from seed will give you a wide variety of choice in cultivars and will give you the greatest opportunity to try a new or different variety of onion. Gardeners in colder areas will need to start their onion seed indoors several weeks before warmer weather.
Planting Tips & Tricks
As a rule of thumb, onions grow their tops in cool weather and form their bulbs when the weather warms. Cool weather boosts the early stages of the onion’s growth, so plant them in spring, except in mild-winter areas, where onions can be grown as a fall or winter crop.
Plant onion seeds 4 to 6 weeks before the last average frost—or start them even earlier indoors, or use a cold frame. When seedlings reach 2 to 3 inches tall, harden them off by exposing them to above-freezing temperatures.
To sow outdoors, sow your seed thickly in rows about a half inch deep. Thin seedlings to 1 inch apart. Thin again about 4 weeks later to approximately 6 inches apart.
To plant bulb sets outdoors, place bulbs 2 inches deep and 4-6 inches apart. Space closer if you want to harvest young plants as green onions. When planting bulbs, plant them with the pointed tip up and the flatter end down.
Keep your onion patch well weeded. Mulch around and in-between plants after the shoots begin to rise and grow.
Provide 1 inch of water each week. Overly dry conditions can cause your bulbs to split.
Go easy on the fertilizer – if your soil is rich in organic matter, your onions will not need it. Too much nitrogen or fertilizer can actually stunt the inner growth of the bulb.
Onions are mostly disease and pest free – but to encourage the healthiest bulbs possible, you should keep the area well weeded and make sure the soil drains well to keep problems at bay.
When your onion tops begin to yellow, bend the stem over with the backside of a rake. This will stop the sap in the stem from flowing and will tell the bulb to mature. A few days later, when the tops turn brown, pull the bulbs up or dig gently. Store in a cool, dry place. You can also dry your onions, braid them, or keep them in a mesh bag for longer storage.