Here's how: Just soften up the dirt with a hand rake in the area you've prepared for your onion bed. Place each onion set right on top of the soil, root side down. Push each one down into the dirt very slightly, just enough to keep it stable, upright, and in place. Put the next one in, about 3-6" away. That's it! The onion set's roots will quickly make their way down into the soil, and green tops will start growing quickly. Any rain will probably push the dirt up around the growing bulb a bit, and that's fine. The top of the onion will stay visible as it grows, which actually makes it easy to see how big it is for harvesting.
Onions are cold hardy, so I plant my spring crop in February and March in my zone 7 garden. In fact, onions don't like heat when in the early growth stages. I've tried growing onions from seed, but the thin blades - like grass - require more time for weeding than I'm willing to invest, and they grow very slowly. Onion sets, which are immature bulbs and look like tiny onions, give a bit of a head start on growth vs. seeds or transplants, and they are less prone to disease. You can usually find them for sweet, red, yellow or white onions; I've grown all types successfully. I've seen them sold in small sacks or sold loose, by the pound. No matter what color onion I plant, they all seem to have a good strong flavor; I once heard that the stronger the onion, the long it keeps. My onions don't store really well, so I use them fresh, or peel/chop/freeze, or cut up and dehydrate. Onions like regular watering during growth; dry weather can cause the bulbs to split. Mulching the onion bed keeps down weeds and holds in moisture. I've never had any bugs or diseases on my onions, which makes them very easy to grow organically.
During the growing season, I harvest onion tops as scallions (as I do with the green tops of garlic), selecting one or two green leaves from each plant rather than cutting the entire top from any one onion. This way the growth of the onion bulb is not affected. You can also dig the bulb up at any time, or wait until the plant tells you it is ready to harvest. Mine are usually ready to dig up in June or July.
When the green tops begin to turn tan, fall over, and die back, withholding water will help the onion cure and increase the storage life once harvested. I wait until a dry spell to dig the onions up. Once dug, I let them dry outside, making it easier to brush off any dirt from the outer skin. Usually I'll lay them on sheets of newspaper in a single layer, shaded from the sun on a table on my porch.
|Clumps of potato onions, planted last fall|
Try some onions in your garden this year!