How to Control Pearlwort in Your Lawn

Pearlwort can be identified by its small, oval-shaped leaves. It’s more widespread and wispy than common broadleaf weeds, but it still falls into this classification. Small, white flowers will bloom briefly through Spring, Summer and warmer parts of Autumn.

 This weed thrives in warm, humid environments and is commonly found along the eastern seaboard of Australia, particularly in Queensland, New South Wales, and northern Victoria.

It tends to invade Buffalo, Couch, Bermuda, Kikuyu, and Zoysia lawns, particularly those that are poorly maintained or experiencing thinning due to drought stress, poor soil health, or overuse.

Pearlwort will grow from seeds that can be easily spread from this low-lying plant, but can also be sprigged from cut sections of the vegetation meaning that a plant could easily shoot off several new plants if hit by a lawnmower or line trimmer.

The seeds can be transported by wind, water, and even on garden tools, shoes, and pet fur, leading to widespread infestations if not managed promptly.

Pearlwort also spreads through underground rhizomes, making it difficult to control by simply manually removing the plant once established.

Manual Removal

It’s possible to manage Pearlwort through manual removal and cultural practices. If the weed is detected early, it can often be removed manually by pulling it out by the roots. This is best done when the soil is moist, as it ensures the entire root system is extracted, reducing the likelihood of regrowth. Mowing regularly at the correct height for your grass type can also help suppress weed growth by encouraging a dense, healthy turf that outcompetes invasive species.

Using Herbicides

Chemical control is the most effective way to manage fast-spreading weeds like Pearlwort. Currently, few herbicides are registered as being effective for Pearlwort specifically, but many common active ingredients like Dicamba, MCPA and Bromoxinyl have shown efficacy in its knockdown.

Contra M Duo is the only broadleaf herbicide registered to control Pearlwort, though both Bow and Arrow and Estate also have ample doses of the necessary active ingredients to manage it.

The efficacy of liquid herbicides can be improved by using a surfactant like Wetter 600 to help the herbicide stick to the weeds, improving first round kill rate. This is especially important given the waxy nature of Pearlwort’s leaves.

It’s also recommended that you abide by the manufacturers recommendation when it comes to application rates, and ensure you’re spraying safely using their recommended protective equipment.

Luckily, invasive weeds like Pearlwort can be managed through the use of a pre-emergent herbicide. Pre-emergent herbicides are a powerful tool that lawn lovers use to neutralise seeds before they even get a chance to germinate, which is a great way to keep foreign flora out of your established lawn. As well as managing seasonal grasses like Poa Annua or wintergrass, a pre-emergent is also incredibly effective at managing undesirable weed outbreaks from plants like Pigweed/Purslane and others, whose seeds are easily spread and can germinate quite quickly.

Pre-emergent herbicides will often provide up to six months cover. They’re typically applied in Autumn to protect lawns through Autumn and Winter, and then again in Spring to cover Spring and Summer.

They are available in liquid form through products like Spartan or Barricade, or can be purchased in granular form through products like Onset GR or Oxafert, the latter of which has the added benefit of a slow release fertiliser.

Mowing regularly at the correct height for your grass type can also help suppress weed growth by encouraging a dense, healthy turf that outcompetes invasive species.

Whether you’re looking at managing an outbreak that you’ve just identified using a broadleaf or selective herbicide, or you think preventing weeds through the use of a pre-emergent herbicide would be more effective, you can purchase common post-emergent herbicides like Contra M Duo (not safe for Buffalo), and pre-emergent herbicides like Spartan, Barricade, Oxafert or Onset GR through the myhomeTURF online store.