The invasive climber Old Man’s Beard has been given more than just a trim in the Pukeokahu district near Taihape. With nine local farmers at the forefront, serious infestations of the pest plant are now in full retreat.
Former Federated Farmers Manawatu-Rangitikei executive member Fraser Gordon says it was about six years ago that the Department of Conservation raised a call to arms. Old Man’s Beard (Clematis vitalba) was running rampant, particularly in the Otuareiawa and Kokopuni stream catchments, smothering native trees and also getting into pine blocks.
Nine farmers agreed to a levy per hectare over a 3,500 hectare area to boost the DoC resources, and at various times Horizons Regional Council, and for the first time this year the Rangitikei River Catchment Group, have kicked in funding.
“They’re all local sheep and beef farmers involved and if we’d had one of them say ‘no’, I don’t think it would have worked,” Fraser said. “Great co-operation has been the key to it.”
Another of the farmers who has been leading the initiative with Fraser, Jock Stratton, estimates that so far more than $140,000 has been spent on the control campaign, and a quarter or more of that has come from farmers.
There’s 14km of steep gorge in the Otuareiawa and Kokopuini Stream areas covering some 210 hectares and a key to the spraying has been Simon Werthmuller’s Rangitikei Helicopters.
In the lower parts of the stream areas Old Man’s Beard “was like a carpet. It was smothering everything,” Jock said.
Over the entire target area, Jock’s estimate is that they’ve now knocked back 90 per cent of the weed.
An irony of Clematis vitalba is that it was first introduced in New Zealand as an ornamental plant in the 1920s because people liked the look of its fluffy seed bolls – the very thing that allows it to be so easily spread by wind. DoC now spends millions of dollars a year trying to control it.
Another irony for the Taihape farmers is that some of the infestations are near waterways, from which they have to exclude animals. Yet sheep quite like eating the weed, “in fact they do quite well on it,” Jock said.
The farmers are grateful to the volunteer group Rangitikei Volunteer Guardians, who have handled all the administration and accounts, saving them from having to set up another entity.
The Pukeokahu control programme has used neso-sulphiran, or the more expensive chlorid, spray. Fraser said a bug from Croatia, which eats the vitalba, is being trialed at Lincoln University but its drawback is that the bug also eats the native clematis.
“They’re now bring a new bug that is Old Man’s Beard-specific and it might be available by Spring. Breeding stations are needed to get their numbers up.”
A difficulty is that sprays can’t be used when the bugs are active.
While Fraser is pleased that the farmer-led initiative has Clematis vitalba on the run in their own district, he’s dismayed to see it rampant in other areas, such as along the back road to Palmerston North.