10 Tips for Growing Larger Onions

Onions grow well in cool weather, so I always add them to my fall garden. Emily is sharing her tips for growing larger onions.

I’m sure you’ve heard the saying onions practically grow themselves. While it’s true they grow themselves unfortunately they don’t always produce large bulbs unless you baby them a little bit. Sometimes you have to do more than the typical correct spacing, fertilizing and watering to get onions to grow larger. Here are 10steps to grow larger onions.

1. Purchase healthy onion sets that are known for large bulbs. Walla Walla Sweet Onion is one that is large.  Onion sets should look good, no rotting visible and have green tops. Seeds should come from an organic company.

2. Space onion sets at least 6 inches away from each other so they have plenty of space to grow large bulbs. You do not need to go more than 10 inches apart but leaving plenty of space to grow is very important to growing larger bulbs.

3. Before planting onions set, remove all rocks and hard soil from bed, dig a trench and fill with loose fertilized soil. An alternative to a trench is to form large rounds of loose soil. Loose soil is easier for the onion to dig its roots in and the bulb will be able to form rounder. Soil conditions are a matter of choice, some growers like a bed of organic matters, some like a shallow bed and others a traditional raised bed. It’s going to depend on the grower and some trial and error to figure out what you prefer.

4. Onions are heavy feeders and like lots of organic matter. Fertilize with lots of nitrogen or bone meal, add chicken or steer manure and some sand to the soil.

5. Water frequently, at least an inch deep every other day but watch bulbs to make sure there is no sign of rotting. If rotting is noticed, remove rotting bulbs and reduce water.

6. Onions don’t have many insect issues but treat infestation as soon as a problem is noticed. Use an organic insect repellent if necessary and pick off visible insects and kill them so they don’t come back.

7. Onions hate weeds, their roots can’t compete with them so remove them frequently. Pull weeds up by hand to ensure the entire root is removed. Place mulch around beds to block out light so weeds don’t form.

8. As onions grow remove soil from the bulb, this helps the bulb form nicely round onions and also encourages growth. You should have already removed rocks and hard clumps of soil before planting the sets but if any rocks are seen remove them. You should be able to see a bulb forming before you start removing any soil.

9. Once your onions have been growing for several months cut half the tops off, this will spark the onion to keep growing. You can do this up to two times without damaging the bulbs. The tops are great as chives, stir fry them or add them to omelets for a nice breakfast.

10. As onions grow, sprinkle azomite on the soil bed and mix in around the onions. Azomite is a mineral and onions love it, they will grow like crazy when this mineral is added to the soil. You can do this throughout the season to help onions grow larger.

Emily is passionate about growing her own food, crafts, sewing, developmental disabilities and blogging. She holds a bachelors degree in psychology with a secondary in human development from Washington State University. She also holds an associates degree in horticulture from Clark College. You can often find her blogging over at Emily’s Frugal Tips, a frugal blog dedicated to teaching families how to live with more for less money.