The track to Tane Mahuta in the Waipoua Forest has been reopened after a week's closure while a new footwear scrubbing station was installed.
The station is being well used by the many visitors to the track, says a Department of Conservation spokeswoman.
Footwear cleaning stations have been put at the start of many tracks leading to kauri trees as extra protection against kauri dieback.
Tane Mahuta, the largest kauri in New Zealand, is more than 2000 years old and is in good health.
However, once a tree gets the spores of the killer kauri disease around its shallow roots, it is usually a death sentence.
The disease slowly starves a tree to death by infecting the roots and destroying tissues that carry water and nutrients. There is no known cure.
People walking through a kauri forest unknowingly spread the infection through their footwear.
The cleaning stations replace the older walk-through system. They have brushes to remove mud and spray bottles with disinfectant for people to apply to the soles of their footwear.