Some weeds are fire-sensitive (fire will either kill or suppress them); however, the susceptibility of weeds to fire varies greatly. In some cases fire is used to kill the weed; in other cases it is used to get access to the weed.
Be aware that some weeds actually benefit from fire. Using fire at times when weed seeds are developing or ripening can help to prevent the release of seeds, but here the timing of the burn is critical. This approach is most effective with annual weeds that depend on each season´s seed crop.
The use of fire as a control method requires detailed planning, such as installing fire breaks, and organising personnel and equipment. In all cases, permits and approvals must be obtained.
Moisture and nutrient control
Some weeds require certain moisture and nutrient levels, and by altering these levels the weed becomes disadvantaged. Some weed infestations occur due to water run-off, where extra nutrients from gardens, paddocks or drains are carried in the water. If this nutrient supply is cut off, weeds are less likely to thrive.
Overlaying weeds with mulch, newspaper or black plastic (solarisation) are other ways of altering the growing environment for the weed, and will usually prevent weeds from germinating. Commercial weed mats are also available.
Over-planting with native species is a long-term weed control strategy. The objective is to establish a canopy that will 'shade out' and outcompete weeds. This method is usually combined with other weed control measures.