There's mounting concern for New Zealand's largest living kauri tree, Tāne Mahuta.
It comes as kauri dieback disease has again been detected within a hundred metres of Tāne Mahuta and a host of other ancient kauri trees in the Waipoua Forest.
The disease is spread by soil movement, and how do you stop that? You wash your shoes.
Which is why this week on Hilary Helps, the Seven Sharp co-host went to Northland to make sure everyone's footwear in the forest was spick and span.