Growing Onions: Some Tips and TechniquesGrowing Onions: Some Tips and Techniques
The onion: it’s in almost every kitchen, but we’d never thought about growing onions until we moved to farm country (Minnesota), where it seems everyone has a huge kitchen garden. Here is where we first learned about short-day and long-day onions, seedlings and sets, and storing these pungent bulbs that add so much to our simple living cuisine.
Onions are another member of the Allium genus, and like garlic, they contain high levels of beneficial nutrients. World’s Healthiest Foods, the authoritative nutrition website, says of onions, “With their unique combination of flavonoids and sulfur-containing nutrients, the allium vegetables such as onions belong in your diet on a regular basis.”
But we would use onions even if they weren’t powerhouses of healthful polyphenols because they taste so good! We add them to beans while they’re cooking, to vegetable/bean filling for burritos, and too roasted root veggies and pasta sauce.
Want to Grow Your Own?
Growing onions is easy if you are patient and know which kind to grow in your part of the world. Here are some points we think are important if you want to grow your own:
Onions can be grown in three different ways: from seeds, from sets, and from transplants. We’ve done all three; each has its advantages and disadvantages.
Onion sets come from seeds germinated last year. They are grown to marble-sized bulbs and then stored over the winter, sold for spring planting, and harvested in the late summer or fall. They are convenient, but can be expensive and don’t keep as well as onions are grown directly from seed. This method is our least favorite way of growing onions.
You can direct-seed onions in the garden in the early spring. This method was frustrating for us because onion seeds take a long time to germinate – it seems like they will never come up! With patience and protection when they’re tiny, this method produces onions which keep well and is the method of choice if you want to grow a lot of onions.
The best method for us is transplanting. Seeds are germinated indoors in flats of potting soil (be patient!), nurtured in the cold frame during late winter, and planted out into the garden when cold weather is past. This method makes the most of every seed, and the onions are grown this way keep well if they’re stored properly.
Another consideration when you’re growing onions is day length. Onions respond to the length of the day to know when it’s time to form a bulb. Different varieties are adapted to different latitudes. In the northern U.S. summer days can be 16 hours long, whereas here in Arizona the longest days are only about 14 hours long. Gardeners in Minnesota grow long-day varieties while growers in Florida grow short-day types. Your seed catalog or garden center will tell you which types are adapted for your latitude.
So you’ve chosen a variety, a growing method, and your onions are lookin’ good. How do you tell when they’re “done”? When the day length is right your onions will form bulbs of golf-ball to softball size, and the leaves will begin to turn yellow and die back. The necks of the onions will soften and the tops will fall over. This falling over is the signal your onions are ready to harvest.
Gently lift them out of the soil with a spading fork and let them dry for a few days in the garden if the weather will allow. If it’s rainy, bring them indoors to a warm dry place. Let the tops dry and the necks thin down. Don’t cut the tops off until they’re completely dry! Store your onions in a cool dry place indoors where there’s plenty of air circulation.
As usual, we recommend you consult our garden articles for more information on vegetable gardening. Good luck and have fun!