New Zealand's clean and green image has come under attack from a visiting UK businessman.
Our use of weed sprays across streams and pockets of native bush was "Neanderthal", said Graham Gibbons.
He and his wife Ruth Larsen have visited her family in Whanganui during most of the last 15 years. They love the Parapara stretch of SH4, but were devastated to see large areas of hilly farmland near Raetihi sprayed off this year.
Mr Gibbons owns a landscaping business in the United Kingdom. He has 13 staff who work mainly on big private estates, including for members of the royal family.
He uses the herbicide glyphosate himself, but only on private property, with approval, and only in small amounts on especially difficult weeds.
"We don't spray it around the base of trees or anywhere near waterways."
Glyphosate is extremely damaging to certain life forms in water courses, he said, and even the version made for use in water is being subjected to tests.
There has been a lot of debate about the herbicide in Europe. The UK has decided it can be used there for another five years, but it has been banned in some countries and has been found in bread and other foods.