Crabgrass removal: A handy guide for Aussie lawns

Crabgrass is one of the most stubborn lawn weeds in Australia, spreading fast in warm weather and choking out healthy grass before you know it's there. If crab grass in Australia has taken hold of your lawn, here's exactly how to identify it, remove it, and stop it from coming back for good.

What is crabgrass and why is it a problem?

Identifying crabgrass early in your garden beds makes it much easier to remove. (Source: iStock)

Crabgrass is a fast-spreading annual weed that thrives in Australia's warm climate, producing seeds and taking root wherever your lawn is thin, bare, or compacted. It's often used as a catch-all term for a few closely related species.

Left alone, crabgrass outcompetes your lawn for water, nutrients, and sunlight, weakening it and leaving it more prone to disease. Its shallow, mat-forming roots don't anchor the soil properly either, which increases the risk of erosion, creates uneven patches underfoot, and stops air and water reaching the soil below.

How to identify crabgrass in your lawn

Early detection is crucial in managing crabgrass effectively. Here’s how to identify this troublesome weed:

• Colour: A distinctive yellowish-green hue, contrasting with the healthy green of your lawn.

• Texture: Leaves are coarse and rough to the touch.

• Leaves: Hairy leaves on the stem.

Not sure how to weed your garden? Learn how to identify and pull out weeds through this guide!

Step-by-step guide to removing crabgrass

Extreme heat or lack of water can leave a lawn dormant. (Source: iStock)

There’s no single fix for crabgrass. It takes a combination of physical removal and ongoing lawn care. Work through these steps for targeted treatment and crabgrass prevention.

Step 1: Hand-pull small infestations

For small patches, pulling crabgrass out by hand is often the quickest fix. Water the area first to loosen the soil, then pull up the entire plant, including the roots, to stop it regrowing from any remaining root fragments.

Step 2: Apply a selective herbicide

For larger infestations, a selective crabgrass killer is your best option. Look for products containing quinclorac, triclopyr, or DSMa--these target crabgrass and similar grassy weeds like summer grass and crowsfoot without harming most lawn types.

Always check the label against your grass species first, as some selective herbicides aren't safe on kikuyu, buffalo, or Queensland blue couch.

Step 3: Mow and water strategically

Mow regularly and keep your grass at its recommended height: taller grass shades the soil, making it harder for crabgrass seeds to germinate.

Water deeply once a week rather than lightly every day, as deep watering builds stronger root systems in your lawn while giving crabgrass less of an edge. Skip fertilising in summer, since the nitrogen boost favours crabgrass growth over your existing turf or grass.

Step 4: Overseed bare patches

A thick, healthy lawn is one of the best long-term defences against crabgrass taking hold again. Bare or thin patches are prime real estate for crabgrass seeds. Reseed these areas as soon as you spot them, and keep them consistently moist while new grass establishes.

How to prevent crabgrass from returning

Investing in professional lawn care and maintenance results in a beautiful lawn and landscape. (Source: iStock)

A healthy, dense lawn is the best long-term crabgrass control. You need regular garden maintenance to keep it from coming back. Here are some tips:

• Mow at the right height and frequency for your grass type

• Water deeply once a week instead of light daily watering

• Avoid fertilising over summer, when crabgrass grows fastest

• Reseed bare patches as soon as they appear

• Rinse mower and gardening equipment between jobs to avoid spreading seed

Find out how much it costs to get a lawn care specialist to maintain your lawn.

Best crabgrass killers available in Australia

A few product types cover most crabgrass problems in Australian lawns:

• Selective herbicides (DSMA-based): Look for products like David Grays Crab Grass and Clover Killer since they target crabgrass, summer grass, and paspalum. However, it may be toxic to other lawns like buffalo and Queensland Blue Couch.

• Pre-emergent herbicides: Apply this in early to mid-spring, before crabgrass germinates, to stop seeds sprouting in the first place.

• Non-selective herbicides (glyphosate): This is effective for spot-treating isolated patches, but they'll kill your lawn grass too, so use with care and only where reseeding is planned.

Always follow label directions for application rate and timing, and avoid spraying on windy days to stop drift onto healthy lawn.

Say goodbye to a weedy lawn!

A lawn without prominent crabgrass is not only visually appealing, but it’s also healthier and more resilient. If crabgrass has spread across most of your lawn, or you're not confident identifying it correctly before you spray, it's worth bringing in a professional. A local lawn care Tasker can treat existing crabgrass, reseed bare patches, and set up an ongoing mowing schedule that keeps it from coming back.