How to control creeping Oxalis in my lawn
Creeping oxalis, or Oxalis corniculata as its formally known, is often mistaken for clover due to its compound leaves with small, light-green, heart-shaped leaflets. Its bright yellow flowers are 3–4 mm in diameter, with five petals in a loose cluster. This weed typically pops up during the cooler months in Melbourne; however, it can occur year-round depending on weather.
Creeping oxalis grows from bulbs deep in your soil, so it can be quite challenging to eradicate. As the name suggests, creeping oxalis quickly runs along the surface of the soil, producing roots and bulbs as it goes. These roots grow deeper into the soil with time, creeping under and through your lawn.
How do I remove creeping oxalis from my lawn?
Hand removal can help if the plant is caught early enough, but more established bulbs can be buried as deep as 100 mm into the soil. The most effective method of control is applying pre-emergent fertiliser such as Oxafert at the start of every season, along with spraying of plants with a selective herbicide such as Bin-Die whenever you see the weed appear. Oxafert provides the soil with plenty of nitrogen, which supports a healthy lawn but creates adverse conditions for oxalis.
Persistence is key when it comes to eliminating this tough weed. While Oxafert should reduce re-occurrence, it may take several years to completely eradicate this weed from your yard.
Fortunately, self-repairing lawns such as Sir Walter DNA Certified Buffalo, Tif Tuf, Sir Grange, and Eureka Premium VG are very forgiving. With time and a little extra fertiliser, any bare patches caused by creeping oxalis will self-repair, returning your lawn to its former glory.