The program, undertaken by a contractor engaged by the Goulburn Broken Catchment Management Authority in July 2025, focused on controlling watsonia, which spreads through both seed and bulb division and has become established along sandy sections of Hughes Creek banks.
Mitchell Shire Council supported the project, which treated the weed during its early growth stage.
As part of the program, a trial compared the effectiveness of a broadleaf selective herbicide and a non-selective herbicide.
Follow-up works carried out this season delivered encouraging results, with monitoring finding significantly fewer re-emerging watsonia plants in treated areas compared with untreated sites, indicating the herbicide applications successfully reduced the bulbs’ ability to regenerate.
The positive outcomes also meant less effort was required during follow-up works, with less than half the time needed to undertake control works compared to the previous season.
The trial found no significant difference in performance between the two herbicides tested, suggesting that timing and targeted application are the most critical factors in achieving successful control.
However, the broadleaf selective herbicide offers an advantage by reducing the risk of impacts on non-target species, making it a valuable option in sensitive environments.
GB CMA health project officer Christine Glassford said the project highlighted the benefits of acting early to control watsonia infestations.
“This project demonstrates that timing is critical when managing watsonia,” Ms Glassford said.
“By targeting the weed early in its growth stage, we were able to achieve better control results and substantially reduce the effort required for follow-up treatment.”
The findings provide guidance for landholders, land managers and environmental organisations looking to reduce the spread and impact of watsonia across the region.
The project is funded by the Victorian Government as part of its commitment to protecting and restoring Victoria's waterways and catchments.
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