Growing Bigger Onions: Why I Trim the Tops and Don’t Let Anything Go to Waste
This summer, I gave my onion patch a little haircut—and it made all the difference. In this post, I’ll walk you through why I trim my onion tops mid-season, how I use those trimmings in the kitchen, and why fertilizing onions as if they are leafy greens leads to bigger bulbs. If you’re looking for a no-waste, practical approach to growing onions at home, you’re in the right place.
🧅 Why I Trim and Fertilize My Onions Mid-Season
As onions grow, their leafy green tops play a direct role in bulb development. Each leaf corresponds to a potential layer in the onion, so the more healthy green leaves you have, the bigger your final bulbs will be.
That’s why mid-season care is so important. Here’s what I do:
✂️ I Trim the Tops—Just a Bit
Around mid-season, I give my onion tops a light haircut—snipping off a few inches if the greens start flopping over or growing too tall. This helps redirect energy into bulb development and prevents the tops from bending, which can reduce photosynthesis and hinder growth. Plus, it keeps my garden tidier and prevents the tops from shading out nearby plants.
Watch my YouTube video here
Bonus: No Waste! Don’t throw out these onion tops! They’re mild and flavorful.
🍽️ How to Use Onion Greens
Here are some tasty and practical ways to use onion tops:
Chop and sprinkle over soups, curries, and salads..
Stir into scrambled tofu for a light oniony bite.
Blend into dips or sauces, like chimichurri, salsa verde, or green goddess dressing.
Add to homemade veggie broth for depth of flavor.
Use like chives on baked potatoes or grain bowls.
Ferment or pickle with other garden veggies.
Dehydrate and grind into onion powder.
Freeze for later use in cooked dishes.
See my YouTube short on freezing and making green onion powder here.
🌿 I Fertilize Like I’m Growing Greens
Onions are heavy feeders—and they thrive with a steady supply of nitrogen during their vegetative phase. I treat them like leafy greens at this stage and give them a boost with a high-nitrogen organic fertilizer (like blood meal, bat guano, feather meal, or a balanced fish emulsion).
Why nitrogen? Because strong leaf growth equals strong bulb formation. Each leaf a plant grows becomes a wrapper layer around the developing onion. More leaves = more layers = larger onions. Do this before the bulbs start popping out of the ground! Once bulbs start emerging, make sure you don’t cover them with soil. They like to sit on top of the soil Their roots are still comfortably in the soil.
🛠️ A Garden Tip Worth Trying
This simple technique of mid-season trimming and feeding has worked wonders in my home garden. My onions are stronger, my garden beds stay neater, and I get an extra harvest without any extra planting.
It’s a small tweak with a big payoff.
🧅 Garden Tip: Onions May Help Prevent Cancer
Onions aren't just delicious—they're powerfully protective. Studies show that allium vegetables like onions contain compounds such as quercetin and sulfur-based phytochemicals that have antioxidant, anti-inflammatory, and potential anti-cancer properties. Regular onion consumption has been linked to reduced risk of several cancers, including stomach, colorectal, and breast cancer. So when you're trimming those green tops or fertilizing for bigger bulbs, know that you're also growing one of the healthiest crops around!
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📚 References
National Cancer Institute – Garlic and Onions: Their Cancer Prevention Properties (Cancer Prevention Research, 2015) AACR Journals
Oregon State University Extension: Growing onions. https://extension.oregonstate.edu/news/no-need-tears-if-you-plant-onions-soon#:~:text=CORVALLIS%2C%20Ore.,when%20they've%20formed%20bulbs
Utah State University Extension: Fertilizing onions. https://extension.usu.edu/vegetableguide/onion/soil-fertility