A controversial inclusion. Most people fall into one of two camps - strongly supporting their use or vehemently opposing any sort of chemical use. We have adopted a pragmatic approach over the years, using chemicals for spot spraying as and when necessary but attempting to minimise their use as best we can.
Personal Protective Equipment
There are two important rules to remember when using chemicals: firstly, dilute your mix as per the instructions (over-egging the mix does not achieve anything other than cost you money and create chemical build-up in the soil); secondly, wear PPE. That means covered shoes, gloves, goggles and if possible a breathing mask. This may seem extreme but these chemicals are not benign and Glyphosate has recently been identified as a proven carcinogen and banned in a number of countries.
Glyphosate (major brand name RoundUp) is a broad spectrum herbicide - that means it kills pretty much any plant it comes in contact with.
To work effectively the entire target plant need to be sprayed. It takes about an hour to become 'rain fast' (use the BOM rader to check if rain is about) and takes about a week to work (although plants will begin to brown within three days).
Although it is generally used for spraying grasses such as Gamba and Mission you can also mix it with kerosene and paint it on freshly cut 'woody' weeds such as Mahogony sapplings.
It comes in various concentrations so read the instructions and mix appropriately and accurately (we use an old jam jar that has been marked at the correct level). Do not spray near waterways or drainage easements.
As mentioned above Glyphosate is currently undergoing a review in a number of countries, so use carefully.
We use this to tackle Snake Weed and Hiptus. It can be used in combination with Glyphosate for increased efficacy. Expensive but effective, the name alone ("friend death") tells you all you need to know about its toxicity.
Brand name 'Taskforce' this is another expensive herbicide - used more often in southern states to tackle serrated grass species it is one of the best methods of tackling Giant Rat's Tail. Unlike the above chemicals Flupropante works by killing the root system of the plant and also kills the seed bank. It needs to be 'rained in', so apply before light rains are expected and it takes many months for results to be seen.
It is available in solution as well as in granular form (which makes application easier).