“She used two simple ingredients — and her onions grew bigger than ever” 🧅✨ No chemicals, no costly treatments — just iron sulfate and birch tar, and the results speak for themselves. Healthier roots, no pests, and a stronger harvest. Want to know how she does it? Full guide in the article below 👇🌿💧🌱
Over the years, I’ve tried different tricks to grow healthy, large onions—but this method has proven to be the most reliable. For several seasons now, I’ve been getting strong, full-sized bulbs without rot or signs of pests. And the secret? Two simple and affordable ingredients: iron sulfate and birch tar.
These two natural remedies work together to protect your onions from both disease and pests—without the need for expensive chemicals.
Why Iron Sulfate Works
Iron sulfate (also called ferrous sulfate) helps defend your plants against fungal infections and gives your onions a much-needed boost of iron. This mineral plays a key role in keeping the green tops from turning yellow and helps onions absorb nutrients like nitrogen more efficiently from the soil.
The Power of Tar
Birch tar is a strong natural disinfectant. More importantly, it has a scent that repels onion flies—a major threat to onion beds. This one ingredient can save you a lot of trouble and prevent damage before it even begins.
Step-by-Step: How I Treat My Onion Sets
Before doing anything, sort through your seed onions and toss any that are dried out, moldy, sprouting, or damaged. Only healthy bulbs should go through the treatment process.
Step 1: Iron Sulfate Soak
In a plastic or glass container (never metal), mix 2 heaping tablespoons of iron sulfate per 1 liter of water.
Soak up to 1 kg of onion sets in this solution for a few hours, giving them a stir every now and then.
After soaking, rinse the onions well with clean water. The bulbs may darken slightly from the solution, but that’s completely normal.
Step 2: Birch Tar Treatment
Mix 2 to 3 tablespoons of liquid soap or dishwashing liquid with nearly a full tablespoon of birch tar, then add it to 1 liter of water.
Soak the onions in this mixture for another couple of hours.
That’s it—no need to rinse again. Once they’re done soaking, the onions are ready to go straight into the soil.
This two-step process not only protects onions from root rot and diseases, but also deters onion flies from laying eggs in the soil. The result? Bigger bulbs, stronger plants, and a harvest you’ll be proud of.
Have you tried natural methods to protect your onion crop? What worked for you? Share your tips or questions in the comments—I’d love to hear how your garden is doing this season!
