Onion Maintenance 101: How to Grow Bigger, Healthier Bulbs

If you want your onions to grow big, firm, and flavorful—not just tall and leafy—then a little mid-season maintenance goes a long way. Onions are one of the more pest- and disease-resistant crops you can grow, but they still benefit from intentional care as the bulbs mature.

Here’s what I do on my homestead to get the most out of each onion plant.

🌿 1. Weed Regularly

Onions hate competition. Their shallow roots and slow growth make them vulnerable to getting crowded out by weeds.

  • Hand weed weekly around your onion rows

  • Avoid deep cultivation so you don’t damage developing bulbs

  • Mulch lightly to suppress regrowth but don’t smother the base of the plants

☕️ 2. Feed the Soil (Coffee Grounds + Super Tea)

Healthy onions need loose, nutrient-rich soil. Mid-season, I give them a boost with two natural amendments:

  • Used coffee grounds: Sprinkle lightly around the base—rich in nitrogen and beneficial microbes.

  • Super Tea Blend: A liquid microbial fertilizer that helps drive nutrient uptake and boost growth.
    Grab the Super Tea Blend here and use code HOMESTEAD for a discount

Apply every couple of weeks after watering, especially if your soil is sandy or depleted.

✂️ 3. Prune the Greens

You can (and should!) cut back the green tops of your onions:

  • Trim the greens down to 6–8 inches once they start flopping over

  • Do this 2–3 times during the season

  • This redirects energy from top growth into bulb development below ground

It also helps reduce the chance of early bolting in variable weather.

🌼 4. Remove Any Flowers

If you see your onion sending up a flower stalk (called bolting), snip it off right away.

  • Flowering means the plant is going to seed and will stop bulb development

  • The earlier you catch it, the more energy can be redirected back to the onion itself

🌱 5. Expose the Bulbs for Better Growth

As bulbs swell, they push up through the soil. You can help them by:

  • Gently pulling back mulch and excess soil from around the bulb shoulders

  • Allowing sun and airflow to hit the bulbs, which helps them firm up and dry out evenly

Avoid burying onion bulbs deeply—they like to breathe!

🐛 6. Natural Pest Resistance & Companion Benefits

Onions are part of the allium family and naturally deter many common pests, including aphids, cabbage worms, and even rabbits.

They’re excellent planted alongside:

  • Carrots (help deter carrot flies)

  • Beets

  • Cabbage family crops

  • Lettuce and leafy greens

They not only protect neighboring plants but also don’t compete heavily for nutrients.

🧅 Wrapping Up

Onions don’t need tons of fuss, but a few simple steps like pruning, weeding, feeding, and exposing their bulbs can make a huge difference in their size and flavor.

And don’t forget—they’re more than just a crop; they’re a natural defender in your garden lineup.

Want more tips like this all season long?
👉 Grab my FREE Garden Toolkit to get planting guides, pest solutions, and crop-by-crop care sent right to your inbox.

Erika Nolan

Erika Nolan is Licensed Horticulturalist with a Certification in Landscape Horticulture. She created Instar Farms from a smaller home business, operating out of 50 s.f. of gardening space. Erika hustled the plant world in every way possible: from selling plants at people’s doorsteps to growing food and selling products at the local Farmer’s Markets. Success allowed Erika to purchase a larger property where she could build her homesteading model. As soon as she built the Veggie Garden, the business exploded as everyone wanted the same: to reconnect with growing their own food. Alongside Edible Gardening, Erika's love affair with plants has led her to other creative Landscaping Services, offering the best, most thought-out ideas, all within sustainable, artistic fashion. Erika considers herself and her team “Garden Artists”, taking the possibilities of the landscape beyond ordinary vision. Green Walls and Garden Art are speciality services of Instar.

https://www.instargardens.com
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