How to Get Rid of Sour Sobs (Oxalis) Naturally – Why They Keep Coming Back Every Winter
- Tammy Johnson
- 3 days ago
- 6 min read
Written and edited by Tammy 3rd July 2026
Sour Sobs (Oxalis) – The Winter Weed Everyone Loves to Hate
Cold, wet winter months, walk outside, and guaranteed somewhere in your garden you’ll find sour sobs!
As little kids, my brother and I would wander around the yard picking sour sobs, a few to give to mum to put in a vase, and a few for us snack on, we’d chew on the crunchy, sour stems. I can still hear Mum’s voice calling out from the back door, “Don’t eat those! They’re sour because the dogs pee on them!”
My brother and I would look at each other, raise our eyebrows, giggle, shrug our shoulders… and eat them anyway.
Eating sour sobs was almost a rite of passage for a 70's kid.
Fast forward to now and I can’t help but smile when I’ve caught my little three-year-old granddaughter doing exactly the same thing. Funny how life comes a full circle.
You can’t miss them.
They’re those cheerful bright yellow flowers standing tall above a carpet of lush green leaves. Every winter they appear by the millions, popping up through the lawn, the garden beds, pathways and even the cracks in the driveway.
Why Sour Sobs Appear Every Winter
Sour sobs (Oxalis pes-caprae) are a cool-season bulb, so they love the cold, damp conditions that winter brings. While everything else in the garden is slowing down for the season, guaranteed the sour sobs will be ramping up. They’re almost like nature’s little calendar, announcing that winter has officially arrived!
Come the warmer weather, they’ve done their work and stored away enough energy for the following season so they die back and disappear (not unlike any other bulbs).
Why’s is It So Hard to Stop Them-Nothing Works
Think of an iceberg.
We’ve all heard the saying, “It’s just the tip of the iceberg.” That’s because only about 10% of an iceberg sits above the water, while the other 90% remains hidden beneath the surface.
Sour sobs are a bit the same (not just because they like the cold! 🥶)
What you’re seeing above the soil is only a tiny fraction of the real problem.
Every single plant is attached to an underground bulb, and over time that bulb produces dozens of tiny bulblets around it. Long before you realise it, hundreds of them can be quietly waiting beneath the surface. Then, when the autumn rains arrive and the soil cools, they all begin shooting at once.
Add to that the thousands of seeds, from the flowers that did have the opportunity to set seed, already lying dormant in the soil, and it’s easy to understand why pulling a few plants rarely solves the bigger problem. In fact, digging can often break up and spread those bulbs even further, creating even more plants for future seasons.
That’s why controlling sour sobs isn’t about winning one battle, it’s about slowly exhausting both the underground bulb bank and the seed bank over several seasons.
So, Here’s How to Manage Sour Sobs Naturally
We should always try to work with nature wherever we can.
Instead of pulling them out, simply chop them down before they have the chance to build up more energy reserves or set seed. A mower, whipper snipper or hoe all work beautifully.
That leafy material becomes free organic matter, it lays there, slowly breaking down into the soil and feeding the worms, fungi and beneficial microbes that make healthy gardens.
Even better, those little roots you’ve left behind continue doing a very important job.
As they naturally die away, they leave behind thousands of tiny channels through the soil. Those little passageways improve water infiltration, allow oxygen to move deeper into the ground and create spaces where your plants roots and soil life can thrive.
Nature has already done the hard work; you might as well take advantage of it.
If they’re growing through your garden beds, add a generous layer of mulch, carboard, autumn leaves, anything organic over the top. Smother them!! Smothering them reduces the light they receive, helps weaken them over time and, at the same time, builds healthier soil underneath.
Patience really is your greatest tool.
Every year you stop the plants from photosynthesising; you’re slowly reducing the energy stored inside those underground bulbs. It won’t happen overnight, but neither did the infestation.
Is Roundup the Answer?
Sometimes, in severe infestations or areas where absolutely nothing else is practical, herbicides may have a place.
But they’re rarely the magic bullet people hope for, and often they kill other non-target plants that weren't intended (like the prized roses!!).
They usually kill the leaves you can see, but they do nothing to stop the countless dormant bulbs and seeds ready to emerge later. That’s why so many people spray year after year and still find themselves asking exactly the same question the following winter.
Sometimes the Weeds Are Trying to Tell Us Something
Believe it or not, those little yellow flowers are actually telling us something.
They’re reminding us that the soil has cooled right down.
The rains have arrived.
The microbes are active.
Earthworms are moving.
Life beneath our feet is quietly thriving.
Our gardens are breathing after another long, dry summer.
So perhaps instead of seeing sour sobs as the enemy, we can simply see them as another sign that winter has arrived, and everything is as it should be.
Give them a quick haircut, leave everything on the ground to feed the soil, spread a little mulch where you can and let nature continue doing what she does best.
Sometimes the healthiest garden isn’t the one with no weeds.
It’s the one with the healthiest soil beneath them.
Happy Gardening
Tam😘🌱
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