How to Remove Winter Grass in Buffalo Lawns

Winter grass (Poa annua) is a cool-season weed that invades warm-season buffalo lawns in subtropical areas like Gympie and the Sunshine Coast. Its soft green tufts and triangular seed heads appear in autumn as temperatures fall, and if left unchecked it can take over, compete for nutrients, and leave bare patches. In this guide we explain what winter grass is, why it’s a problem in buffalo lawns, and how to control it with effective weed control practices.

What Is Winter Grass and Why Is It a Problem in Buffalo Lawns?

Winter grass (Poa annua) is a low-growing grassy weed that germinates as soil temperatures drop. It has distinctive drooping leaves and seed heads with triangular shapes. In Gympie and Sunshine Coast winters (around 12–20°C), it can begin sprouting as early as March–April and continue through the cooler months, often peaking in late winter.

Because buffalo grass is a warm-season variety, its growth slows in cool weather. This means that while buffalo lawns may go somewhat dormant (turning a dull green or slightly yellow in winter), winter grass thrives and spreads quickly. The weed’s rapid life cycle and prolific seeding can make it very difficult to eradicate once established.

Left unchecked, winter grass forms dense clumps that crowd out healthy buffalo grass and deplete soil moisture and nutrients. It also dies off in spring, leaving unsightly bare patches in your lawn. Removing it promptly is crucial, because allowing it to go to seed “brings seven years of weeds” – each plant drops thousands of seeds that germinate next season. In short, winter grass is an annual weed that can overwhelm a weakened buffalo lawn, so early identification and action are key.

Prevention Strategies

A strong, healthy buffalo lawn is your first line of defense against winter grass. Prevention combines good cultural practices with timely herbicide use.

• Proper Mowing: Keep buffalo turf at the correct height (about 3–5 cm). This height shades out weed seedlings and prevents winter grass from flowering and setting seed. Never scalp the lawn by cutting off more than one-third of the grass blade at a time, as that weakens the buffalo and allows weeds to invade. Raise the mower deck slightly in cool weather if needed, since buffalo grows slower in autumn and winter.
• Good Drainage and Soil Aeration: Winter grass likes compacted, poorly drained soils. Improve drainage and soil aeration so buffalo roots grow deep and strong. Core-aerate the lawn in spring or autumn to relieve compaction and encourage healthy root growth. Well-aerated soil helps buffalo establish a robust root system that outcompetes shallow-rooted weeds.
• Regular Fertiliser and Watering (Building Buffalo Health): A well-fed buffalo lawn is less susceptible to winter grass. Apply a complete fertiliser in late summer or early autumn to strengthen buffalo before winter. Use a buffalo-specific winter fertiliser or slow-release blend as fall arrives. Water deeply but infrequently – for example, a good soaking once or twice a week in autumn. Deep watering encourages the buffalo’s deep roots and discourages shallow-rooted winter grass. In winter, reduce watering (buffalo grows slowly) to avoid waterlogging that can promote weeds and disease.
• Timing of Pre-Emergent Herbicides: The most effective prevention is a pre-emergent herbicide applied in early autumn, before winter grass seeds germinate. Products like Barricade (with prodiamine) or Oxafert can be applied around March–April in our region to form a soil barrier that stops Poa annua seed from sprouting. Always follow label instructions and apply on a calm day. This step greatly reduces future weed pressure by preventing the seedbank from germinating.
• Seasonal Monitoring: Keep a close eye on your lawn as temperatures cool. Inspect for tiny clumps of winter grass in shaded or damp areas. The moment you see it, take action – whether by hand-pulling or spot treatment – to prevent larger infestations. In early autumn, even before weeds appear, plan your pre-emergent spray to beat the germination window.

By combining mowing, feeding, watering, and strategic herbicide timing, you can greatly reduce the chance of a winter grass outbreak.

Safe and Effective Removal Methods

If winter grass is already present, a combination of manual and chemical methods will clear it out while protecting your buffalo grass.

Manual Pulling

For light infestations, manual removal can be effective. Use a weeder or hand tool to loosen the soil around each winter grass plant, ideally after watering. Water your lawn before removal to soften the soil and make pulling the weeds easier. Grasp each tuft near the base and pull firmly, making sure to remove the entire root. Poa annua has relatively shallow roots, so it usually comes out with a gentle tug. Dispose of the weeds (do not compost them) to prevent any seeds from spreading. Repeat as new weeds appear; small infestations can sometimes be managed entirely by hand if caught early.

Herbicide Treatments

For larger or persistent infestations, herbicides are often necessary. It is critical to choose products labelled safe for buffalo lawns. Buffalo is a sensitive grass, and many broad-spectrum weedkillers will injure or kill it along with the winter grass. Always look for selective herbicides marked as “safe for buffalo” or “turf grass safe” on the label.

• Pre-Emergent Herbicides: These are the best preventive chemical measure. A pre-emergent like Barricade can be applied in early autumn. Apply according to label directions, and water it in lightly so it forms a barrier in the soil. This will prevent new winter grass seeds from germinating. Typically this is done once per year in our climate. Barricade Pre-Emergent (dithiopyr or prodiamine) is commonly recommended for winter grass control.
• Post-Emergent Herbicides: Once winter grass has emerged, use a selective post-emergent grass killer to spot-treat it. Products like Amgrow Winter Grass Killer are formulated to kill Poa annua without harming buffalo. Apply on a calm, cool day following the instructions, and avoid mowing for about a week afterwards to allow the herbicide to work fully. For example, Amgrow Winter Grass Killer targets the roots of Poa and should be sprayed early in the weed’s lifecycle, ideally before seed heads form. Other options (available at garden suppliers) include Embargo (a pre-emergent) or tailored grass herbicides safe for buffalo. Always spot-spray; never blanket-spray the whole lawn or spray when buffalo is stressed.
• Caution with Non-Selective Herbicides: Non-selective herbicides (glyphosate/Roundup) will kill buffalo if they come into contact. Use these only as a last resort and very carefully, for example by “painting” them on the winter grass foliage with a brush so that the buffalo is not affected. In most cases, selective pre- or post-emergents are safer and sufficient.

The table below compares the main control methods:

After treatment, continue to monitor the lawn. Sometimes multiple spot treatments are needed during winter if new seedlings emerge. Always follow the label instructions and safety guidelines for each product.

Natural Removal Techniques and Boosting Buffalo Health

While chemical controls are effective, you can also use natural methods and lawn strengthening to keep winter grass at bay:

• Organic and Manual Methods: Besides pulling, some people try natural remedies (vinegar, boiling water, corn gluten, etc.), but these can damage buffalo or are unreliable. The best “natural” tactic is to starve the weeds by thicken­ing your buffalo stand. For example, after removing winter grass, overseed bare spots with fresh buffalo sod or seed. We offer premium buffalo varieties like Sapphire Buffalo that establish quickly and help crowd out weeds. Mulching removed weeds or using mulch on thin areas can also suppress some germination (though be careful not to smother the buffalo).
• Improve Lawn Health: A healthy buffalo lawn naturally suppresses weeds. Follow a regular maintenance routine: fertilise buffalo in autumn and spring, aerate annually, and keep thatch at bay. Remove lawn clippings if you see winter grass seed heads, to avoid spreading the seed. Maintain a proper watering schedule (deep and infrequent) and mow at the recommended height. For instance, the Sapphire Buffalo variety should be mown to 2–5 cm, and in winter only mowed every 3–6 weeks. This helps keep the grass dense. Lower cutting heights or skipping mowing allows weeds to set seed and should be avoided.
• Fertilising Strategy: Use a balanced fertiliser that is not too high in nitrogen in winter (which could encourage weeds). A slow-release, winter-formulated lawn fertiliser will strengthen buffalo grass without a quick green-up that weeds like. Follow fertiliser schedules appropriate for QLD: for example, Sapphire Buffalo is often fertilised twice a year (early April and September). Strengthening the buffalo with nutrients will help it outcompete any remaining winter grass in the following spring.

In summary, the key to “natural” control is making your buffalo lawn as vigorous and dense as possible so that weeds have little room to establish. Good mowing, watering, feeding, and airflow all contribute to a healthy turf that chokes out winter grass.

Post-Removal Care and Seasonal Schedule

Once you’ve cleared the winter grass, follow a seasonal care plan to keep it away and maintain a lush buffalo lawn:

• Autumn (March–May): After clearing debris, apply a pre-emergent herbicide before soil temperatures fall below ~15°C, usually around April in our region. This prevents new winter grass seeds from germinating. Rake out any remaining dead weeds and overseed or lay turf in bare spots. Fertilise lightly to build strength before winter.
• Winter (June–August): Buffalo grass will grow very slowly. Mow infrequently – perhaps once a month or as needed – keeping a height of 3–5 cm. Water minimally (around once every 2–3 weeks unless there’s rain) to keep the lawn from drying out, but never waterlog it. Perform spot treatments on any winter grass that appears, and pull up any new clumps. Avoid heavy foot traffic on the lawn to prevent compaction and yellow patches. As Buffalo grass (like Sapphire) is highly cold resistant, it can stay green all year with proper care.
• Spring (September–November): As warmer weather returns, buffalo will green up and thicken. If needed, apply a balanced spring fertiliser in early September to boost recovery. Aerate the lawn if it was compacted, and continue mowing at the recommended height (more frequently as growth picks up). Keep an eye out for any residual weeds; by now most winter grass should be gone. In autumn/winter, you can repeat a light pre-emergent if clumping recurs, but usually a single annual application is enough.
• Summer (December–February): Buffalo thrives in heat. Mow weekly or biweekly at around 3–5 cm, and water deeply once per week if rain is lacking. Feed in late summer if your lawn shows signs of nutrient need. Winter grass will be dormant in hot weather, so focus on overall health to prevent it next season.

You can customize this schedule to your lawn’s needs. Roberts Turf Supplies offers an 8-Week Lawn Care Programme which provides a detailed regimen of mowing, feeding, and treating your lawn through seasonal change.

Common Mistakes to Avoid

• Using the Wrong Herbicide: Many weedkillers kill all grasses, including buffalo. Always use a product specifically labeled safe for buffalo lawns when tackling winter grass. Using a non-selective or inappropriate herbicide can kill your buffalo grass and still leave the weed behind.
• Mowing Too Short: Cutting buffalo too short weakens it and allows sunlight to reach weed seeds. Never remove more than one-third of the grass blade length at a time. During winter, raise the blade height slightly (toward 5 cm) to protect buffalo and shade out weeds.
• Neglecting Winter Maintenance: Some assume “nothing grows in winter”, but buffalo still needs care. Skipping all maintenance in winter lets weakness set in. Keep an eye on the lawn and handle issues promptly. A little attention prevents big problems.
• Over-application of Herbicides: More chemicals is not better. Only apply herbicide when needed and according to label. Overdosing can injure buffalo lawns. Use spot treatments for patches, and don’t spray the entire lawn unnecessarily.
• Spreading Seeds: Mowing or edging with no catcher can fling winter grass seeds around. Always collect and dispose of clippings that contain seed heads. Clean tools between yards to avoid cross-contamination.
• Poor Lawn Care Practices: Failing to mow regularly, water deeply, or fertilise correctly will weaken buffalo. A thin or stressed lawn is exactly what winter grass loves. Follow good care practices year-round to keep buffalo vigorous.

By avoiding these mistakes and following the prevention and removal steps outlined above, you can greatly reduce winter grass impact.

Frequently Asked Questions

• Q: What does winter grass look like?
  A: Winter grass (Poa annua) forms low, soft clumps with light-green drooping leaves. It often has seed stalks with triangular seed-heads that appear in winter. You’ll notice it early in the cooler season as bright green patches or distinct clumps in your lawn.
• Q: How do I tell winter grass from buffalo grass?
  A: Winter grass grows in tufted clumps and is a lighter shade of green. Buffalo is generally broader-leafed and slower growing in winter. If you dig up a clump of the suspect grass and see easily pulled shallow roots, it’s likely Poa (winter grass). You can also spot seed heads – buffalo does not produce the same light triangular seed heads that Poa does.
• Q: When should I apply herbicides for winter grass?
  A: For prevention, apply a pre-emergent herbicide in early autumn (March–April) before soil temperatures allow Poa seeds to germinate. For existing winter grass, apply post-emergent selective herbicides any time you see active growth, typically in winter. Always choose a calm day and follow label directions on timing and re-entry.
• Q: Are Barricade and Amgrow products safe for buffalo?
  A: Yes, Barricade (pre-emergent) and Amgrow Winter Grass Killer (post-emergent) are commonly used on buffalo lawns. Barricade is a pre-emergent herbicide that won’t harm established buffalo when used as directed. Amgrow Winter Grass Killer is formulated to kill Poa annua while being safe on buffalo. Always double-check the label to ensure the product lists “buffalo” or “warm-season turf” as safe turf types.
• Q: Can I just use vinegar or salt to kill winter grass?
  A: Home remedies like vinegar, salt, or boiling water will also kill buffalo grass and often aren’t effective on deep roots. They are not recommended for lawns. It’s best to pull small weeds or use approved herbicides for larger infestations.
• Q: How can I encourage my buffalo lawn to outcompete weeds?
  A: The key is a thick, healthy turf. Mow at the correct height, fertilise in autumn and spring, aerate, and water deeply. A dense buffalo lawn will naturally choke out most weeds. Use quality buffalo seed or turf (such as Sapphire Buffalo, which remains green in winter) to repair bare spots quickly. Regular maintenance and avoiding over-watering are crucial for a weed-free lawn.

Keeping winter grass out of your buffalo lawn is not a once-off task, but an ongoing process of prevention, timely treatment, and strong lawn care practices. By staying consistent with mowing, feeding, aeration, and using the right herbicides at the right time, you’ll not only control winter grass but also maintain a healthy, lush buffalo lawn all year round.

If you need expert advice, premium buffalo turf, or tailored support, Robert’s Turf Supplies is here to help—whether you’re in Gympie, the Sunshine Coast, or anywhere in between. Explore our turf varieties or talk to us about our professional turf services and discover how easy it can be to keep your lawn looking its best.