Biosecurity – Wilding Pines

May 2022

Waging war on the self-seeding wilding pines in the Marlborough region.

Wilding pines are one of many biosecurity issues threatening the Marlborough region. The community-based South Marlborough Landscape Restoration Trust is partnering with the Marlborough District Council, and volunteers from wineries and other local businesses, to wage war on the self-seeding wilding pines – pinus radiata, contorta pine and Douglas fir – which pose the biggest plant threat to New Zealand’s environment. 


With wilding pines a long-standing issue in Marlborough, the South Marlborough Landscape Restoration Trust (SMLRT) was established in 2016 by a concerned group of current and former high country farmers to help restore and protect the iconic scenic tussock grassland and alpine landscapes and increase the area’s biodiversity. 


They understood wilding conifer control required long-term commitment from both local and national agencies, as well as their community.


Trust chair, John Oswald, says the it has the resounding support of landholders in Awatere Valley and the areas surrounding Te Hau/The Ned, as well as teaming with local businesses to provide staff time to help with the effort, among them vineyards in the region including Tohu Wines, Kono Wines and Yealands Wine Group. Four of the seven trustees are either farmers or retired farmers and all have close associations with the Awatere district.


Like the community group combatting Chilean needle grass, raising the money to get the work done is critical and John is proud to say the trust has so far been able to raise $1 million from various sources. Farmers are 100 per cent in support, he says, and have contributed funds, as have the New Zealand Lotteries Commission, the Rata Foundation, the Vavasour Trust (local winery) and others. 


Experienced forester, Ket Bradshaw, is the trust’s coordinator. She says wilding pines threaten an area of 870,000 hectares, all the way from south of the Wairau River and the foothills of Blenheim to the Clarence and Molesworth Station in the south.


“Our goal is to control, and where possible eliminate, wilding pines in South Marlborough and advocate for Government funding to control the wilding pine problem in the Branch and Leatham Conservation Area, arguably one of the worst infestations in New Zealand. “We started in the Awatere Valley in 2018 and currently our operational area covers more than 130,000 hectares.”


She says there are several methods of removing the wilding pines. One involves cutting the tree and pasting the raw stump with a herbicide mixture, another is drilling holes in the trunk and filling the hole with the herbicide mix, or, if the tree/seedling plant is small enough, pulling it out of the ground.  


A keen environmentalist, Ket says controlling wilding pines is also essential in increasing native biodiversity and helping to improve the ecosystem. “Added to this, the control of wilding pines is ensuring the cultural, historical and recreational values of the area are protected – and reduces the risk of devastating wild fires and protect waterways and water yields.” 


Wilding pines (pinus radiata, contorta pine and Douglas fir) pose the biggest plant threat to New Zealand’s environment. Self-seeding, the trees spread aggressively, overwhelming productive pastureland and native landscapes to the point where they destroy native plants and habitats. 


If left unchecked, wilding pines could take over a quarter of New Zealand’s landscape within the next 30 years – a $4.6 billion dollar threat to the national economy.


While some wilding pines have spread from commercial forestry, the major issues stem from the practice of planting pine trees for the stabilisation and prevention of soil erosion in decades past.


The work that Ket and her teams are involved in are part of the Wilding Pine Network, an incorporated society involved in advocacy and advice. Membership is comprised of organisations and individuals involved in wilding conifer/pine management and research. 


The Network advises the National Wilding Conifer Control Programme, led by Biosecurity New Zealand/MPI on good practice and engagement with communities, as well as advising community groups, trusts, and iwi. The Network is holding a conference in Blenheim from 13-15 September 2022. For the registration link and other information, go to: