City of Stirling has recently set-up a trial for caltop which includes:
– Encourage caltrop infestations to be reported to the City
– Remove the caltrop and the bulk of seed-containing soil
– Plant perennial ground cover plants to out-compete the Caltrop and discourage future growth of the weed
– Map the caltrop infestation in our database and regularly inspect the site for future outbreaks
– Install signage advising the public of the presence of Caltrop at that site
– Continue to research additional new approaches and techniques including methods to force-germinate all dormant seed remaining within infested soil, so that mass-removal can be conducted.
– Work with private land owners to encourage effective caltrop control on land which is outside of our direct control.
City of Joondalup is looking at passing a local law to compel owners to remove caltrop from their land:
If you haven’t experienced caltrop, count yourself lucky. My record occurred on the Trek trial with my father and older brother. We had around 10 flats on that trip, following hitting a caltrop patch outside Northam.