- Last updated:
- 04 Jan 2022
Council conducts research trials to monitor the effectiveness of control methods including:
- manual removal
- mechanic controls
- new technologies such as solarisation
These research trials are important for the ongoing fight against invasive plants. Over time species may become resistant to a particular herbicide or new technology arises. Pest Plant officers aim to provide up to date and informed advice to assist landholders manage weeds on their properties.
Council has been trialing the use of biodegradable Jute weed matting to suppress the growth of weedy Sporobolus sp. grasses along several roadsides
Invasive Sporobolus sp.
Conondale, Cambroon, Witta, Kenilworth and Verrierdale
Suitable areas for trials were identified taking into consideration the amount of invasive Sporobolus grass present, safety of undertaking the trial and ability for the trial site to remain undisturbed.
The Sporobolus grasses were brush-cut down to near ground level and then the Biodegradable Jute weed matting was laid out over the area. At one site larger clumps of Sporobolus grass were taken out before laying down the weed matting and native grasses were sown on top of the weed matting once it was showing signs of breaking down (after around 12-18 months). At the trial site in Verrierdale, lomandras (a drought tolerant native plant) were planted in the weed matting (at 50cm apart).
Monitoring of this control method over several years proved that using the biodegradable weed matting (without any revegetation) was successful in initial suppression of the growth of invasive Sporobolus grass though overtime invasive Sporobolus spp. returned.
At the trial site where larger clumps of Sporobolus were taken out initially and the area was reseeded with native grasses less invasive Sporobolus spp returned once the matting had broken down.
The greatest success was the trial site at Verrierdale where no invasive Sporobolus spp. were present after 3 years and over 70 percent of Lomandra plants had survived. The success is likely due to the ability of Lomandra to suppress the regrowth of invasive Sporobolus once the weed matting had broken down.
Council has been trialing the use of solarisation to suppress the growth of weedy ground covers
Singapore daisy (Sphagneitcola trilobata)
Thick black builders plastic was laid out over the area and weighed down. The plastic was then left for 6 months. After 6 months the Singapore daisy had died and most had decomposed.
Council assisted with the trial of solarisation to suppress the regrowth of running bamboo shoots after they had been cut.
Running bamboo (Phylostachys spp.)
Thick black builder’s plastic was laid out over the area of cut bamboo stumps and weighed down. The plastic was then left for 12 months. After this time there had been no regrowth apart from in the areas where the black plastic had broken and light was able to get in. The large starch reserves that bamboo contain mean that it requires significantly longer time without sunlight to ensure that regrowth does not occur. This site is still being monitored.