Mixing rates depend on the product, the weed and the equipment, so no single number fits every job. This page gathers the rates printed on the current manufacturer labels for three herbicides we stock, together with the label restrictions that go with them. We checked the figures against the labels on 28 October 2026. Labels are updated from time to time, so always read the label on your container before you mix.
How to read a rate
- Per 100 L of water is the usual rate for handguns and larger sprayers. Divide by 100 to get mL per litre.
- Per 15 L is a knapsack tank. Multiply the per-100 L rate by 0.15 (for example, 350 mL per 100 L is 52.5 mL in a 15 L knapsack).
- Rates depend on the weed. Use the row for your weed, its size and the season.
Grazon Extra: rates per 100 L of water
Grazon Extra (Corteva, APVMA approval 60830/147022) contains 300 g/L triclopyr, 100 g/L picloram and 8 g/L aminopyralid (Group 4). These rates are from the high volume spraying table on the label.
| Weed | Growth stage on the label | Rate per 100 L of water |
|---|---|---|
| Blackberry (with docks, ragwort, smartweed, thistles) | Late spring to autumn | 350 mL or 500 mL (use the higher rate on plants damaged by grazing stock or insects, and on known difficult blackberry) |
| African boxthorn | Less than 2 m tall, good leaf cover | 500 mL |
| Cape, English and flax-leaf brooms | Spring to mid-summer, before pod formation | 250 mL |
| Gorse | 1 to 1.5 m tall, spring and summer only | 250 mL |
| Groundsel bush | 1 to 1.5 m tall, spring to summer | 250 mL |
| Paterson’s curse | Flowering | 250 mL |
| Capeweed | Flowering | 150 mL |
| Rubber vine (not rust-infected) | Up to 1.5 m tall, at flowering | 350 mL |
| Green cestrum | Late spring to early autumn | 500 mL |
For blackberry 1 to 2 m tall, the label gives a spray volume of 3,000 to 4,000 L per infested hectare. The label lists many more weeds, so check it for yours.
Key label restrictions
- Do not burn off, cut or clear blackberry or other woody weeds for at least 6 months after spraying.
- Do not apply to weeds that are stressed (not actively growing) from cold, drought, waterlogging or previous herbicide treatment.
- Do not spray if rain is likely within 1 hour or if the foliage is wet from rain or dew.
- Corteva only recommends knapsacks or 12 volt sprayers for low-growing herbaceous weeds and for woody weeds that are not regrowth and are less than 60 cm high or across.
- Picloram and aminopyralid can stay active in the soil, and the product is damaging to susceptible plants, including tomatoes, vegetables, fruit, ornamentals and flowers. Keep spray and drift away from them.
- In Tasmania there is a limitation for blackberry: do not treat bushes carrying mature or near-mature fruit.
- Mix only with water. Half-fill the tank, add the product, then add the rest of the water with the agitator running.
Grazon Extra 1L and Grazon Extra 5L are in our range.
Concussion 540 K glyphosate: rates
Apparent Concussion 540 K (APVMA approval 80392/124029) contains 540 g/L glyphosate as the potassium salt (Group 9). It is a non-selective herbicide with no residual weed control.
| Use | Handgun | Knapsack |
|---|---|---|
| General weed control: home gardens, commercial, industrial and public areas | 7.0 mL per litre of water | |
| Annual weeds | 330 to 480 mL per 100 L | 50 to 70 mL per 15 L |
| Perennial weeds | 470 to 660 mL per 100 L | 70 to 100 mL per 15 L |
The label has further rows for woody weeds and for specific weeds, with higher rates and comments, so check it if you are treating those.
Key label restrictions
- Apply when weeds are actively growing and wet the foliage completely and evenly. Visible symptoms can take 3 to 7 days.
- Do not disturb weeds by cultivation, sowing or grazing for 6 hours of daylight after treating annual weeds, or 7 days after treating perennial weeds.
- Do not treat weeds under poor growing conditions, such as moisture stress, waterlogging or severe frost.
- Do not apply where spray drift could reach susceptible crops or plants, in winds under 4 km/h or over 12 km/h, or in inversion conditions.
- Do not spray across open water or let spray enter water. In dry drains and channels, do not apply to weeds growing in or over water.
Concussion 540 1L and Concussion 540 5L are in our range.
Woody Extra: rates per 100 L of water
Apparent Woody Extra (APVMA approval 93213/138295) contains 300 g/L triclopyr, 100 g/L picloram and 8 g/L aminopyralid. These are some rows from the high volume and low volume tables on the label.
| Weed | Growth stage on the label | Rate |
|---|---|---|
| Blackberry (high volume) | Late spring to autumn | 350 mL or 500 mL per 100 L (higher rate on damaged or difficult blackberry) |
| African boxthorn (high volume) | Less than 2 m tall, good leaf cover | 500 mL per 100 L |
| Angophora and banksia (high volume) | 1 to 3 m tall | 350 mL per 100 L |
| Blackberry (low volume, gas-powered gun or sprinkler sprayer) | Late spring to autumn | 335 mL per 10 L of water |
The label table has many more weeds, and some rows go above these rates, so use the row for your weed.
Key label restrictions
- Do not burn off, cut or clear blackberry or other woody weeds for at least 6 months after spraying.
- Do not spray if rain is likely within 1 hour or if the foliage is wet from rain or dew.
- Do not apply to weeds that are stressed (not actively growing).
- Aminopyralid and picloram stay active in the soil for extended periods. In northern NSW and Queensland the label says not to plant susceptible crops for up to 9 months after application.
- Apparent only recommends knapsacks or 12 volt sprayers for low-growing herbaceous weeds and for woody weeds that are not regrowth and are under 60 cm high or across.
Woody Extra 1L and Woody Extra 5L are in our range.
Dicamba M for lawns
For broadleaf weeds in lawns, see our Dicamba M mixing guide, which covers the rate per litre, rainfast time and which lawn types it suits.
Frequently asked questions
How much Grazon Extra do I put in a 15 L knapsack for blackberry?
The label rate for blackberry is 350 mL or 500 mL per 100 L of water, which is 52.5 mL or 75 mL in 15 L. Use the higher rate on difficult or damaged blackberry. Corteva only recommends knapsacks for woody weeds that are not regrowth and are under 60 cm, so use a high volume sprayer for larger bushes.
How much Concussion 540 K do I use per litre of water?
For general weed control in home gardens and commercial or industrial areas, the label rate is 7.0 mL per litre of water. Specific weeds have their own rates in the label tables.
How long does Concussion 540 K take to work?
The label says visible symptoms can take 3 to 7 days to develop. Do not disturb the weeds by cultivation, sowing or grazing for 6 hours of daylight after treating annual weeds, or 7 days for perennial weeds.
When can I cut or clear blackberry after spraying Grazon Extra or Woody Extra?
Both labels say not to burn off, cut or clear blackberry or other woody weeds for at least 6 months after spraying.
Can I mix Grazon Extra with glyphosate?
The Grazon Extra label lists glyphosate 450, metsulfuron-methyl, Roundup CT, Starane Advanced and Statesman 720 as compatible. Follow the directions and restrictions on every label you mix, and check the label before mixing it with any other glyphosate strength.
Is it safe to use Grazon Extra or Woody Extra near vegetables and garden beds?
Both products can damage susceptible plants, including vegetables, fruit, ornamentals and flowers, and picloram and aminopyralid can stay active in the soil. Keep spray and drift away from garden beds and do not plant susceptible crops until the label’s re-cropping period has passed.
Where to buy in the Gold Coast
Browse our herbicide range, or call 07 5537 4585 and we will help you check a product against its label. Orders are dispatched within 24 hours from our Gold Coast store, delivery starts from $17 and is priced by weight and postcode at checkout, and in-store pickup at Arundel is free. The 20 L drums are in-store pickup only.
Last reviewed: 28 October 2026. Rates are from the manufacturers’ labels on that date. Always read and follow the product label.