Bindii in your lawn? Here is how to stop the prickles.

Most people only think about bindii in November, when they walk on the lawn barefoot and feel it. By then it is too late for that season. The prickle you are standing on is the seed, and once that seed has formed and hardened, killing the plant does not remove it.

But there is a second reason to spray, and in spring it is the one that matters. Every plant you kill before its burrs drop is seed that never reaches the soil for next autumn. That is the difference between one bad season and several in a row.

What bindii is and why the timing works the way it does

Bindii (Soliva sessilis) is a winter annual broadleaf weed. Its entire life plays out inside 1 year and the sequence never changes.

It germinates in autumn as soil temperatures drop. Through winter it grows as a low flat rosette, no more than 5 to 10cm across, with fine feathery leaves that look like a carrot top or a sprig of parsley. It is bright lime green and it sits flat enough that a mower passes straight over it. Most people never notice it at this stage.

Then in spring, from around August through to October, it flowers and sets seed. The seed pod is the prickle. That is the entire point of the plant. Everything it does through winter is preparation for that one moment.

The two windows, and what each one achieves

Winter, June through August, is the ideal window. The plant is small, actively growing, and has not yet flowered. Spray then and the seed never forms at all. Nothing goes into the lawn and nothing goes into the soil.

Spring, September and October, is the second window and it is still worth taking. By now the plant is mature and the burrs are forming or formed. Spraying will not remove prickles that have already hardened this season. What it does is kill the plant before those burrs drop and add another year of seed to your soil.

That matters more than it sounds. The bindii seed bank stays viable for years. Every season you let a crop seed, you are funding the next several. Spraying in September when you have missed the winter window is not a wasted application. It is the one that stops the problem compounding.

Mature plants take longer to die and may need a second pass 4 to 6 weeks later. That is the trade-off for treating late rather than early. It is still far better than doing nothing until next winter.

How to be sure it is bindii

Get down and look at it properly. Bindii grows flat to the ground in a rosette, spreading outward rather than upward. The leaves are finely divided, almost like a fern, and bright green. There is a small flower at the centre of the rosette that is easy to miss.

It is not winter grass. Winter grass (Poa annua) is a grassy weed with fine blades that grows in clumps, and it needs completely different treatment. That distinction decides which product works and it is the single most common mistake we see. We cover the full split in winter weeds taking over your lawn.

What to spray

Bindii is not a tough plant. Treated with the right selective herbicide while it is actively growing, it dies. Killing bindii has never been the hard part. The hard part is that almost nobody treats it while it is still worth treating.

Bow and Arrow is the product we recommend and it is registered specifically for bindii. It is a selective broadleaf herbicide with 3 active ingredients: MCPA at 300g per litre, clopyralid at 20g per litre, and diflufenican at 15g per litre. The rate is 50ml in 2 to 5 litres of water per 100m2 through a pressure sprayer. A 500ml bottle treats 1,000m2 and costs $55.

It works more slowly than the fast burn broadleaf herbicides. Expect up to 6 weeks for complete death, faster on small plants. That slowness is the feature rather than the fault. The quick products scorch the leaf and the weed recovers from its root system. Bow and Arrow takes the whole plant and there is no regrowth.

The label is specific on a few points and they matter:

• Apply to actively growing weeds. Do not spray if the lawn or the weeds are stressed, or if frost is coming.
• From September onward, spray early morning or late afternoon. MCPA can cause temporary discolouration in heat or on a lawn already under stress. Water the lawn well the day before and avoid spraying above 30 degrees.
• Apply at least 4 hours before rain so it absorbs through the leaf.
• Do not mow for 3 to 4 days either side of spraying.
• Transient discolouration can occur on kikuyu, carpet grass, and Queensland blue couch. It passes.
• Some buffalo varieties, ST85 in particular, react more strongly. Test a small area first.
• Do not use it on bent grass or winter grass species.
• Diflufenican has residual activity in the soil. Do not oversow treated areas for 3 months.
• Repeat in 3 weeks if new bindii germinates after the first pass.

Stop the next generation before it germinates

Bow and Arrow kills what is already up. It does nothing to seed still sitting in the soil.

To stop next autumn's crop germinating at all, apply Spartan pre-emergent in April, before soil temperatures drop and the seed germinates. Spartan creates a herbicide zone in the top layer of soil that blocks root development in germinating seedlings. Applied at the right time it is the difference between spraying bindii every year and not having it at all.

One caution worth knowing: a pre-emergent gives roughly 4 to 6 months of residual protection depending on rate. An application made too early in autumn can thin out before the main bindii germination flush arrives. Time it to the germination window, not to the calendar.

Why bindii got into your lawn in the first place

This is the part no herbicide fixes. Bindii is an opportunist. It establishes in lawns that are thin, compacted, and dry, in soil that is short on nutrition and slightly acidic. It does not force its way into a dense lawn, because there is nowhere for it to go. Every bindii seed needs a gap and bare soil to germinate into.

So you can spray every single winter for the rest of your life, or you can build a lawn that stops handing bindii somewhere to land.

That starts with the soil. Soak at 200ml per 100m2 breaks the water repellency in hydrophobic soil so water reaches the root zone rather than running off into the low spots where weeds sit. Vital at 100ml per 100m2 uses natural auxins and Vitamin B1 to drive the lateral root development that thickens the turf and closes those gaps. Base at 120ml per 100m2 conditions the soil biology with Tasmanian Bull Kelp so the whole root zone functions properly. All 3 go on together in the same sprayer and get watered in immediately.

Through winter, Vivid at the reduced 100ml per 100m2 rate holds colour in the leaf. Apply it to the leaf and leave it 2 hours before watering in.

Spray the bindii now. Build the lawn so that next autumn there is nothing for the seed to germinate into. Those are 2 different jobs and you need both.

Complete the program

If your lawn is thin enough that bindii has taken hold, the Starter Pack is the right entry point. It covers Soak, Vital, and Surge for $150, which is the foundation most Australian lawns need before anything else will hold.

The Turf & Surf 5-step program sets out the full monthly routine, every product, every layer, every month. A dense lawn is the only weed control that works permanently.

Frequently asked questions

When is the best time to spray bindii in Australia?
Winter through to very early spring, while the plant is actively growing and before the seed pod forms. In most of Australia that means June through August. If you have missed that window, spray anyway. It stops this year's seed reaching the soil even though it will not remove prickles that have already hardened.

It is already September and the prickles have formed. Have I missed it?
For this season's prickles, largely yes. For next season, no. Spraying now kills the plant before the burrs drop, which is what stops the seed bank growing. A mature plant takes longer to die and may need a second application, but treating late is far better than waiting until next winter and starting from a bigger seed bank.

I sprayed in summer and the prickles were still there. Why?
Because the prickle is the seed, not the plant. By summer the plant has already done its job and the seed is in the lawn. The herbicide killed the plant exactly as it was designed to. It just cannot un-form a seed that has already hardened. Spray in winter next year instead.

Is bindii the same thing as winter grass?
No. Bindii is a broadleaf weed with flat feathery leaves in a rosette. Winter grass is a grassy weed with fine blades growing in clumps. Broadleaf herbicides have no effect on winter grass, and this is where most people waste their money. If you are not sure which one you have, send us a photo at info@turfandsurf.com.au.

Can I just pull bindii out by hand?
For a small patch, yes. It is shallow rooted and comes out easily. Get the roots and do it before the seed sets. For anything beyond a few square metres it is not realistic, and any plant you miss still seeds the lawn for next year.

Will bindii come back next year if I kill it this year?
If seed from previous seasons is already in the soil, yes. That seed bank stays viable for years. This is why the lawn itself matters more than the spray. Killing the plant before it seeds stops you adding to the bank, a pre-emergent in April stops what is already in there from germinating, and a dense lawn with healthy soil stops anything that does germinate from finding a gap.