If there's a property in your neighbourhood that you believe is a health or safety hazard due to an unkempt section, you might first try talking to the property owner.
If this does not resolve the problem, contact us on (04) 237 5089 to report a concern that does not present a fire risk, such hoarding and other nuisance issues including vermin control.
If your concern is a fire risk, you can let Fire and Emergency New Zealand know about your concern by completing the online form available for Overgrown sections or call 0800 336 942. Please note that Fire and Emergency is only able to take action to deal with genuine fire hazards, and not where the property is just unsightly or presents a health hazard.