Tauranga City Council has been called out for not doing enough to stop the use of potentially poisonous chemicals to kill weeds as part of a nationwide spray-free campaign.

Last year Tauranga City Council began trialling alternatives to the common weedkiller glyphosate, but Green Party MP Steffan Browning said the council's trials were narrow and not nearly enough.

Mr Browning made presentations to both the city council and Western Bay of Plenty District Council, urging them to eliminate the use of glyphosate in public places.

Glyphosate was a common herbicide, found in commercial sprays such as Roundup and used by councils nationwide.


It was classified as "probably cancer-causing" to humans.

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"Councils should be reaching and trialling as many alternatives as they can, but Tauranga City Council's range of alternatives they are trialling is narrow."

Western Bay of Plenty District Council was not using or trialling any alternatives, Mr Browning said.

The city council trialled a mixture of pine oil and fatty acids as an alternative between October and March, to kill weeds on selected walkways and neighbourhood reserves.

The fatty acids contained plant-derived agrichemicals.

Spraying not only destroys the target pest or plant but also the social biology which keep our plants thriving.


Mr Browning hoped council would look at a wider range of alternatives, such as physical labour like weed trimmers or hot water treatments.

While he acknowledged Roundup was commonly chosen to use in private yards, using it in public places removed any choice.

Mr Browning said economics seemed to be the biggest struggle councils faced. Alternatives tended to cost more and require more labour.

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Tauranga City Council Parks and Recreation manager Mark Smith said results from the trials were not yet available, nor could he provide any detail about the cost difference between glyphosate and the alternatives.

"[There is] an indication that it costs more to achieve the same level of service with pine oil and fatty acids. Once we receive the results, staff will prepare a briefing report for elected members to consider next steps."

A council press release from last year stated its use of glyphosate had decreased 32 per cent since 2009, despite increases in the amount of reserve land it managed.

Western Bay of Plenty District Council could not be reached for comment before this story went to print.

Village Ridge Garden Centre employee Nicole Beets said glyphosate was not as bad as made out.

"Glyphosate as a whole, used as it is supposed to be, is quite safe.

"Roundup, which has been around for a really long time, has ingredients in it which makes it dry within two hours so unless people are getting down and eating the grass it's not going to affect them," she said.

She said the issue with alternatives was they were not nearly as effective. For instance, pine oil dehydrates the part of the plant sprayed but would regerminate after only a couple weeks.

Lily Tworogal, garden co-ordinator at The Rock Papamoa Community Garden, said: "Spraying not only destroys the target pest or plant but also the social biology which keep our plants thriving."

She said pine oil would still cause harm to soil biology, and thought perhaps a cultural perception of benign weed species being undesirable should be shifted.