Amgrow Winter Grass Killer 100mL – Selective Herbicide for Couch & Buffalo Lawns

Selective Winter Grass Control for Couch and Buffalo Lawns

Amgrow Winter Grass Killer is a selective post-emergent herbicide that targets winter grass in established lawns, taking out the weed while leaving compatible turf in place when used as directed. It controls winter grass after it has come up, which makes it a practical fix once you can already see the weed tufting through your lawn. This concentrated 100mL bottle contains 175 g/L endothal and treats a good-sized area, so it suits most home lawns.

How It Works on Winter Grass

Winter grass, or Poa annua, is a light-green tufting weed that throws up pale seed heads and spreads fast once it sets seed. This herbicide works on the actively growing weed, so the key is to treat it early, before those seed heads form. Getting on top of it early matters, because mature winter grass drops large amounts of seed that come back to haunt the lawn in following seasons.

Which Lawns It Suits

The registered label lists winter grass control in Blue Couch, Common Couch, Bent grass, Buffalo and Brown Top lawns. It should not be used on Kikuyu or Fescue lawns, on unidentified turf, or on lawns under severe heat or moisture stress. If you are not certain what type of lawn you have, identify the turf first before applying any selective herbicide, as using it on the wrong grass can damage the lawn.

How to Mix and Apply

Shake the bottle, then measure 15mL of concentrate into 10 litres of clean water and agitate thoroughly, keeping it agitated as you spray. This 10-litre mix treats around 100m² of lawn. Do not add a wetter, surfactant or spray oil. Apply as an even, fine spray while the winter grass is actively growing, from autumn through spring, and repeat with two to three treatments spaced roughly 10 to 14 days apart where needed. Do not spray when temperatures are above 25°C, and avoid spray drift onto garden plants you want to keep. Only mix up as much as you will use on the day.

Timing: Treat Before Seed Heads

For the best long-term result, treat winter grass before it flowers and sets seed. Spraying it once seed heads have formed may kill the existing plants, but it will not stop the seed that has already developed from staying in the lawn and germinating later. Early identification, and treating as soon as the weed appears each season, gives you far better ongoing control.

Key Features & Benefits

• Selective post-emergent control of winter grass (Poa annua)
• Suitable for compatible Couch, Bent, Buffalo and Brown Top lawns
• Contains 175 g/L endothal
• Treats approximately 100m² per 15mL mix
• 100mL bottle treats up to around 660m² in total
• Applied as a fine lawn spray, no wetter required
• Best used before winter grass forms seed heads

Product Details

• Product: Amgrow Winter Grass Killer
• Type: Selective post-emergent lawn herbicide
• Active constituent: 175 g/L endothal (as the dipotassium salt)
• Target weed: Winter grass (Poa annua)
• Pack size: 100mL
• Application rate: 15mL per 10L of water (treats approx. 100m²)
• Suitable lawns: Blue Couch, Common Couch, Bent grass, Buffalo, Brown Top
• Not for: Kikuyu, Fescue, unidentified or stressed lawns
• Brand: Amgrow

How to Use

Always read and follow the label directions, and wear appropriate protective equipment when mixing and spraying. Identify your lawn type first to make sure it is compatible. Mix 15mL of concentrate into 10 litres of water, agitate well, and apply as an even, fine spray over the affected area while the winter grass is actively growing and before seed heads appear. Apply two to three times, 10 to 14 days apart, avoiding application above 25°C. Bare patches can generally be resown about two weeks after the final treatment.

Frequently Asked Questions

What does Amgrow Winter Grass Killer control?
It selectively controls winter grass (Poa annua) in compatible established lawns, targeting the weed while leaving suitable turf in place when used as directed.

Which lawns can I use it on?
The label lists Blue Couch, Common Couch, Bent grass, Buffalo and Brown Top lawns.

Can I use it on Kikuyu or Fescue?
No. It is not suitable for Kikuyu or Fescue lawns, or for unidentified turf. Identify your lawn type before applying.

How much do I mix?
Mix 15mL of concentrate into 10 litres of clean water, which treats approximately 100m². Do not add a wetter or surfactant.

How many applications are needed?
Two to three applications, spaced roughly 10 to 14 days apart, where required.

When should I apply it?
Apply from autumn through spring, as soon as winter grass appears and before seed heads form, and not when temperatures are above 25°C.

How much lawn does the 100mL bottle treat?
At 15mL per 100m², the 100mL bottle contains enough concentrate to treat up to around 660m² in total.

Where can I buy Amgrow Winter Grass Killer in Australia?
It is available online from BPG Supplies (Bonnyrigg Produce & Garden Supplies), with shipping across Australia and local pickup in Bonnyrigg, South-West Sydney.