What is Nutgrass and How to Get Rid of it?

That persistent, upright weed with the telltale triangular stem – you know it, you probably loathe it. That's nutgrass (Cyperus rotundus),and it can be a real headache for homeowners, no matter your chosen turf variety. While our climate in Victoria can be kind many popular lawn types, nutgrass thrives here too, often popping up seemingly overnight to spoil your lush green carpet.

At HG Turf Group, we understand the frustration of battling this tenacious weed. That's why we've put together this practical, no-nonsense guide specifically tailored to Melbourne and regional Victorian conditions and your lawn type, so you can finally win the war against nutgrass.

Why is Nutgrass Such a Pest?

Our warm summers and relatively mild, sometimes wet winters provide ideal conditions for nutgrass to flourish. It's a perennial weed, meaning it comes back year after year, spreading through underground tubers (rhizomes) and tiny nut-like structures (tubers) that can survive even harsh conditions. These tubers can lie dormant for extended periods, making complete eradication a multi-pronged effort.

Identifying Nutgrass

Before you declare war, make sure you're dealing with the right enemy. Nutgrass has distinct characteristics:

• Triangular Stem: This is the most reliable identifier. Roll the stem between your fingers – if it feels triangular, it's likely nutgrass. Grass stems are round or flattened.
• Upright Growth: Nutgrass grows taller and more upright than most common lawn grasses.
• Yellow-Green Colour: Often a lighter, more vibrant green or even yellowish compared to your turf.
• Smooth, Waxy Leaves: The leaves are narrow and smooth with a slightly waxy feel.
• Seed Heads: In late summer to autumn, it produces distinctive clusters of brownish-purple spikelets at the top of the stem.

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The Bad News: Nutgrass and Your Turf Variety

Nutgrass isn't particularly fussy about its neighbours. It can infiltrate many lawn types:

• Buffalo: Its dense growth can sometimes slow the initial spread, but once established, nutgrass will compete for nutrients and sunlight, creating unsightly patches.
• Kikuyu: Kikuyu's vigorous growth habit can sometimes outcompete less established nutgrass, but mature infestations require targeted removal.
• Couch: Nutgrass stands out starkly against the finer texture of Couch lawns, making it visually disruptive.
• Tall Fescue: Its clumping nature can create gaps where nutgrass can readily establish and spread.

The Practical Action Plan: Removing Nutgrass

1. The Immediate Attack: Hand Pulling (For Small, Isolated Patches)

For small, isolated patches of nutgrass, hand pulling can be an effective first line of defence.

The best time to undertake this task is after rain or a thorough watering, as this softens the soil and makes it easier to extract the entire plant, including the crucial underground tubers. To do this effectively, grasp the base of the stem firmly and pull slowly and steadily upwards.

The key is to try and remove the underground tubers intact. If the stem breaks off at the surface, you've likely left tubers behind, which will unfortunately lead to the regrowth of the nutgrass. Diligence is paramount; even a single missed tuber can quickly lead to a renewed infestation.

When hand pulling, particularly in established lawns like Buffalo or Kikuyu, take care not to damage the surrounding runners. For denser turf varieties such as Couch, work methodically to avoid tearing the existing grass.

2. The Targeted Chemical Strike: Selective Herbicides(For Larger Infestations)

When dealing with more widespread nutgrass infestations, a targeted chemical strike using selective herbicides is often the most practical solution.

It is absolutely crucial to choose the right herbicide for your lawn type. Avoid using glyphosate (Roundup) on your lawn, as this non-selective herbicide will kill your turf along with the nutgrass.

Instead, look for herbicides specifically labelled for nutgrass control that are safe for your specific lawn variety. These products often contain active ingredients such as halosulfuron-methyl or bentazon.

In terms of timing, apply these herbicides during periods of active growth, which typically span from spring to early autumn. This is when the nutgrass is actively photosynthesising and will therefore absorb the chemical most effectively.

It's also wise to avoid spraying during periods of extreme heat or drought stress, conditions that can be common in some regional Victorian areas during the summer months.

Always follow the manufacturer's instructions on the product label precisely. Over-application can damage your lawn. If a single application is not sufficient and dormant tubers in the soil start sprouting later you may need to repeat the applications as recommended on the product label.

3. The Long-Term Strategy: Promoting a Healthy, Dense Lawn

A crucial long-term strategy for preventing nutgrass and other weeds is to cultivate a healthy, dense lawn.

Consistent mowing at the recommended height for your specific turf variety is a key component of this. A thick, healthy lawn naturally shades the soil, making it a less hospitable environment for nutgrass seedlings to establish themselves.

Adjust your mowing frequency according to the seasonal growth patterns, with more frequent mowing during the active spring and summer months potentially helping to suppress the development of nutgrass seed heads.

Proper watering practices are also essential. Water deeply and less frequently to encourage the development of deep root systems in your turf, which will make it more resilient to competition from weeds. Avoid shallow, frequent watering, as this can favour shallow-rooted weeds like nutgrass.

Nutgrass often thrives in poorly drained, compacted soils. Therefore, consider aerating your lawn annually, especially if you have clay-heavy soil, which is common in many areas. Core aeration is a particularly effective method for improving soil drainage.

Finally, ensure your lawn receives balanced fertilisation using a quality lawn fertiliser that is appropriate for your turf type and the current season. A well-nourished lawn is better equipped to compete with unwanted weeds.

Check out our guide to maintaining your natural turf.

Top HG Turf Tips for Getting on Top of Nutgrass

• Timing is Key: Act early! Smaller infestations are much easier to control than well-established ones.
• Persistence Pays Off: Nutgrass is a tough weed. Be prepared for a sustained effort over several months, to achieve significant control.
• Prevention is Better Than Cure: Maintaining a healthy, dense lawn is your best long-term defence against nutgrass and other weeds.

Don't let nutgrass ruin your beautiful lawn! By understanding this persistent weed and implementing a targeted, turf-specific approach, you can effectively manage and even eradicate it.

For further advice tailored to your specific lawn and location in Victoria, don't hesitate to contact the team at HG Turf Group on 1800 622 340. We're here to help you achieve the lush, weed-free lawn you deserve.