How to get rid of crabgrass

Lawn and gardening enthusiasts know how crabgrass can creep its way into your tended green space–and how frustrating this can be. Managing it proactively is important to keep your lawn looking its best. This blog post will share some tips on how to remove crabgrass yourself, so you can enjoy a lush, green lawn all year round.

How to identify crabgrass

Crabgrass is a common lawn weed that can quickly spread and take over your healthy grass if left unchecked. Also known as crab weed, it thrives in warm climates and produces seeds prolifically throughout the year. This weed often takes root in areas of bare soil, compacted ground, or where the lawn has been disturbed and often requires more work and professional gardening help.

Crabgrass is a collective term for several species, but the most well-known is Digitaria sanguinalis, which was introduced to Australia in the 19th century.

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.

Why is it important to remove crabgrass?

If you think crabgrass is just an annoying weed with a funny name, you are sorely mistaken. It’s a serious threat to your lawn’s overall well-being as well as your property’s value, by extension. Left unchecked, this invasive weed can quickly take over your lawn, creating a patchy, unappealing sight.

Many property owners are curious to know how to get rid of crabgrass in their lawn because it produces a massive amount of seeds, which also readily germinate and spread. This rapid proliferation allows it to outcompete other grass species and rob them of water, nutrients, and sunlight. This, in turn, weakens your lawn and makes it more susceptible to disease and damage.

In addition, crabgrass also makes a shallow, mat-forming root system that fails to anchor the soil effectively. As a result, it increases the risk of erosion and creates uneven surfaces that can be dangerous for foot traffic. This ‘mat’ also prevents air and water from reaching the soil, further degrading the quality of other desirable plants.

Removal methods: how to get rid of crabgrass

If prevention is no longer an option, here are four tips on how to eliminate crabgrass (in your lawn or otherwise):

1. Proper lawn maintenance

Lawn mowing pros recommend mowing your lawn frequently and maintain the recommended lawn grass height. Deep watering once a week is better than light daily watering. If the soil feels moist, you don’t need to water. This will keep your grass healthy and strong, making it harder for crabgrass seeds to gain purchase.

Avoid fertilising in summer, when crabgrass is most likely to sprout; the nitrogen in fertiliser actually encourages growth. Pay close attention to local weather conditions as they play a big role in lawn maintenance.

Cover bare soil around your lawn with mulch to prevent weeds from popping up. And if you have a gardener or landscaper who looks after your lawn, ask them to rinse off their gear before they start working. This will help prevent the spread of crabgrass seeds from other areas.

2. The organic method

In Australia, you can explore effective natural methods on how to get rid of crabgrass to help reclaim your lawn.

First, reseed any bare spots in your lawn as soon as possible. Don’t let those patches sit around! Get them reseeded right away to prevent crabgrass from taking root.

Second, keep your lawn tall. Aim for a grass height of about 7.5 cm. This will shade out crabgrass and make it harder for it to thrive. A professional lawn mower can help you keep the desired lawn grass height.

Lastly, mow your lawn regularly, especially in the summer, to slow down crabgrass growth. 

3. Pre-emergent herbicides

Pre-emergent herbicides, which come in granules or liquid form, create a protective layer on the soil surface, stopping crabgrass before it can sprout.

To be effective, you need to apply these herbicides well before the growing season, such as when you fertilise your lawn. After applying a pre-emergent herbicide, water the lawn thoroughly. However, you might need to apply the herbicide a second time, depending on the situation.

Always follow label instructions and use the correct amount for your lawn size to get the best results. If you’ve recently reseeded your lawn, wait at least three months before applying any pre-emergent herbicides.

4. Home remedies

You can try a few home remedies to tackle crabgrass. Sprinkling table salt can help, but be careful not to use too much, as it can damage the soil. You can also pour boiling water directly on it.

A known crabgrass killer (and other unwanted lawn weeds) is a white vinegar and soap solution. Mix four litres of white vinegar with a few drops of soap, then spray it on the crabgrass. This can gradually kill it off.

How do I prevent crabgrass growth in my lawn?

A healthy lawn is the best defence. Below are some practical tips:

• Proper lawn maintenance is key to creating an environment that’s less inviting to this pesky weed. 
• Regular mowing at the right height helps keep your lawn thick and strong, making it harder for crabgrass to get a foothold.
• Deep watering once a week, rather than light daily watering, encourages deep root growth, making your lawn more resilient. 
• Avoid fertilising in summer—the hot summers in Australia makes crabgrass grow much more quickly, and the nitrogen in typical fertilisers just fuels the infestation.

As a last resort, you can opt for artificial grass. It eliminates the problem entirely by replacing your natural lawn, thus removing the environment where crabgrass thrives. That said, artificial grass can be a significant investment and may not be suitable for everyone.

Say goodbye to a weedy lawn!

From natural remedies to professional advice, we have explored all the ways on how to kill crabgrass and enjoy a lush, green lawn. A lawn without a single crabgrass plant is not only visually appealing, but it’s also healthier and more resilient.

If you’re struggling with how to get rid of crabgrass, don’t hesitate to seek advice from a local gardening and lawn care professional. They can help you develop a tailored plan to keep your lawn looking its best year-round.

---

FAQs on how to remove crabgrass

What will kill crabgrass but not the lawn?

Pre-emergent herbicides are your best bet for preventing crabgrass before it sprouts. But don’t just get the first weed killer for crabgrass that you find.

For existing crabgrass, selective herbicides, like those containing quinclorac or triclopyr, target crabgrass specifically, leaving your desirable lawn grasses unharmed. Always read the label carefully and follow the instructions for safe and effective use.

Other post-emergent herbicides, such as those containing fenoxaprop p-ethyl and mesotrione, are also formulated to control related species.

Will vinegar kill crabgrass permanently?

Vinegar can help stop crabgrass, but it’s not a permanent solution. This is because it kills the above-ground parts of the weed but won’t necessarily kill the roots. For long-term control, you’ll need to combine vinegar with other methods, like regular mowing and re-seeding bare spots.

Is it better to pull or spray crabgrass?

Pulling crabgrass can be effective for small infestations, but it’s time-consuming and difficult to remove all the roots. For larger infestations, many landscapers and gardening professionals recommend crabgrass herbicides, which are a more efficient solution. However, it’s important to choose a selective herbicide, such as those mentioned above.