Onions are true garden superstars. They’re healthy, delicious, and honestly pretty low-maintenance once they get going. It’s no surprise they’re a staple in almost every backyard veggie patch. However, growing onions from scratch—meaning from seeds—does take a little more elbow grease than other methods.
Sowing Onions
Most folks go the easy route by planting onion “sets” (those tiny little bulbs). It’s less work, and it’s almost foolproof for beginners. But if you’re an experienced gardener looking for a fun challenge, sowing onion seeds is the way to go. The extra effort really pays off: onions grown from seed actually store better and are much less likely to “bolt” (go to seed prematurely). Once you’re holding those firm, homegrown bulbs in your hand, you’ll forget all about the extra work!
Getting the Prep Right
Onions love a sunny spot, and they actually appreciate a bit of a breeze. When it comes to soil, they aren’t too picky, but they do best in loose, loamy soil that’s been cleared of weeds. You’ll want to work some organic fertilizer into the ground a few weeks before planting. Onions are “light feeders,” meaning they don’t need a ton of nutrients. In fact, too much fertilizer can actually lead to disease or stunted growth. If you’re planning to plant in the spring, you can even prep the soil with fertilizer the previous fall.
You can either harvest your own seeds or grab a packet from the garden center. Store-bought seeds almost always have a great germination rate. If you’re using your own saved seeds, it’s a good idea to test them first: drop them in a glass of water—viable seeds will sink to the bottom, while the duds will float on top.
How to Sow Your Seeds
Technically, you can start sowing as early as February, but the ground is usually still too soggy then. You’re usually safe by late March or early April. Of course, you can also start your seeds indoors on a windowsill or in a greenhouse. Just make sure to keep the temperature between 60°F and 65°F (16-18°C).
Quick Facts for Sowing Onions
- Plant seeds about half an inch (1 cm) deep.
- Keep your rows about 8 to 10 inches (20-25 cm) apart.
- Aim for a spacing of 2 to 4 inches (5-10 cm) between individual onions.
- The ideal germination temperature is between 60°F and 65°F.
- Expect to see sprouts in about a month.
- Keep the area tidy—onions hate competing with weeds!
