The most common reason native plantings fail is competition from weeds. Herbicides, when used responsibly, are one of the best ways to keep these weeds at bay. However, there is very little information on how susceptible most native plants are to commonly used herbicides, meaning that when we use them in the field we need to either be very careful or take unwelcome risks.

With support from the Brian Mason Trust, we were able to test the herbicide tolerances of five understudied species common in our restoration plantings to herbicides used in the field. This research involved 700 plants. We identified greater than expected vulnerability to the broadleaf weed control herbicides clopyralid and triclopyr, new opportunities to make better use of these chemicals, and confirmed that drift from a powerful herbicide during careful use around native plants causes no unintentional harm in most species. We've also collated information from this study and many other New Zealand studies to form a guide for field workers on known herbicide vulnerabilities and tolerances in native plants.

Read our report from this study here

Download our guide for field workers here