Oxalis Invasion: Why Early Removal Is Essential in Phillip Island and Bass Coast Gardens

Oxalis removed from one of our Inverloch Gardens

As we move into autumn across Phillip Island and the Bass Coast, one stubborn weed is starting to pop up everywhere — Oxalis pes-caprae, commonly known as soursob or yellow oxalis.
Recognisable by its clover-like leaves and bright yellow flowers, this invasive weed can quickly take over garden beds, lawns, and even mulched areas if not managed early.

Seeds and Dormant Bulbs

Oxalis pes-caprae is particularly difficult to control because it doesn't rely heavily on seeds to spread.
Instead, it produces tiny underground bulbs (called bulbils), which can lay dormant in soil and mulch for long periods until conditions are right for them to sprout.
When the cooler, wetter conditions of autumn arrive, these bulbs wake up — and within weeks, a full carpet of oxalis can appear if left unchecked.

Why Proper Removal Matters

When it comes to controlling oxalis, like other weeds such as bridal creeper, simply pulling out the leaves isn’t enough.
It’s critical to remove the entire root system, including the small black bulbs attached to the roots.
If even a few bulbs are left behind in the soil, the plant will quickly regrow — often more thickly than before.

When weeding by hand:

• Loosen the soil carefully around the base

• Gently remove the entire plant with bulbs attached

• Dispose of the material properly (do not compost)

For larger infestations, targeted weed control strategies may be needed.

Remove Before It Flowers

The best time to remove oxalis is before it flowers.
Once it blooms, oxalis can spread even further, and the energy the plant stores in its underground bulbs makes it even harder to eradicate in the next season.
Early removal in autumn keeps your garden cleaner and reduces the problem next year.

How We Can Help

At Bass Coast Backyards, we specialise in garden maintenance across Cowes, Cape Woolamai, Newhaven, San Remo, and surrounding areas.
We can help identify, manage, and remove stubborn weeds like oxalis and bridal creeper — using careful, effective methods that protect your soil and your plants.

Need a hand controlling oxalis or other invasive weeds in your lawn or garden?
Get in touch with Bass Coast Backyards today for expert weeding and seasonal garden care.