Lupins, considered an invasive weed, cover hundreds of hectares of a South Wairarapa farm.
A South Wairarapa farm’s environment is being blighted by an invasive weed, but the farmers have been told by authorities they are on their own in attempts to control its spread.
Ben and Georgie Lutyens own Riversdale Station, a farm near Wairarapa’s remote south coast.
They estimate that lupins have taken over about 202ha of their farmland, an area that was expanding.
They also grow wild on some of the district’s public roads.
Both Greater Wellington Regional Council (GWRC) and South Wairarapa District Council (SWDC) said they were unable to help eradicate the plants.
While GWRC had a pest management programme, lupin control was not part of it because it would have limited chances of success.
SWDC does not manage pest control.
“There is not a single positive aspect of the lupin infestation,” the Lutyens said.
“Some of our neighbours are equally affected; it is spreading up the rivers and will undoubtedly, in due course, spread to the forest park, if it’s not there already.”
GWRC director of delivery Jack Mace said the council understood the frustration caused by lupins on private land, but while they could give advice, control of the plant was the owner’s responsibility.
“We know this can incur cost for landowners,” he said.
The Lutyens cite a litany of adverse environmental and economic consequences caused by the plant’s dense growth, including affecting dotterel habitat, providing cover for predators, and impacting stock.
“We have a dotterel predator protection scheme in our wide gravel riverbeds.
“Before the invasion of the lupins, the gravel riverbeds were wide and open.
“Now, the lupin provides habitat for predators like hedgehogs, ferrets, rats and feral cats.
“On pasture land, they reduce the grazing available to stock.
“They grow so thickly together that cattle have trouble getting through them, and tall enough that even cattle can’t be seen.
“Other weeds like variegated thistles grow amongst them and seem to thrive.
“When growing in the river beds, they are easily washed out by floods and then get caught in the floodgates, causing them to fail.”
They said lupin control was resource-intensive, in terms of spray, machinery and time.
“On a farm, there is never enough time to get all the jobs done,” they said, saying they needed assistance to help combat the weed.
“Wherever we have controlled it, it has come back.”
They said they had approached the regional council but had been given limited assistance.
Over the past three years, they estimated they had paid the regional council about $20,000 in rates, more than $7000 this year.
Mace said in the Wellington region, GWRC managed dozens of pest plants in accordance with the regional pest management plan.
“The plan sets out our pest control objectives, including which organisms are actively managed.
“Generally, there is a strong likelihood we can contain or eradicate these species.
“Lupins are widespread and common across New Zealand and the Wellington region.
“As such, we cannot justify the expense of a regional lupin control programme that would have very limited success.
“Such a programme would reduce the resources we apply to actively managing other species within the plan to protect our region’s biodiversity, primary production, and social and cultural wellbeing.
“While we can provide advice on lupin management, controlling the plant is the responsibility of landowners.”
A spokesperson for SWDC said its oversight of the issue was limited.
“The control of pests is not a function of South Wairarapa District Council,” they said.
“Our land transport activity has budget for weed spraying within the road corridor to maintain a clear water table and culverts, and to improve road safety and line of sight by keeping vegetation from encroaching onto the road.”
AgPest, which worked with AgResearch to help farmers, said the plant had many negative environmental impacts, including affecting native bird habitat, making it hard for native species to regenerate, and blocking river and stream flows, causing channel diversion and sometimes flooding.
- LDR is local body journalism co-funded by RNZ and NZ On Air.