Battling Wilding Pines: Identification & Cut ‘n’ Paste Control Guide

Seemed like a good idea at the time! That statement is so true of Pine trees, originally introduced in the 19th and 20th centuries to New Zealand for fast timber, erosion control, and shelterbelts. These trees produce light, winged seeds that travel miles on high winds – we call these “wilding pines” or “wilding conifers”.

Wilding pines are basically conifers that have “gone rogue” and they are one of the single greatest threats to New Zealand’s iconic high country, native grasslands, and delicate catchments.

Left unchecked, wilding pines transform open tussocklands and native bush into dense, water-draining monocultures. Unlike commercial or managed forestry plantations, wildings hold no timber value due to their unpredictable growth, uneven spacing, and irregular wood quality.

The Wilding Pine Threat: Key Species & Distribution

Common Wilding Pine Species:

• Contorta / Lodgepole Pine (Pinus contorta)
• Corsican Pine (P. nigra)
• Scots Pine (P. sylvestris)
• Dwarf Mountain Pine (P. mugo)
• Douglas Fir (Pseudotsuga menziesii)
• Radiata / Monterey Pine (P. radiata)
• Maritime Pine (P. pinaster)
• Ponderosa Pine (Pinus ponderosa)
• Bishop Pine (Pinus muricata)
• European Larch (Larix decidua) (Key non-Pinus wilding conifer)

Invaded Habitats & Quick Stats:

• Vulnerable Ecosystems: High country tussocklands, alpine herb fields, native bush margins, geothermal sites, coastal dunes, braided riverbeds, reserve margins – and more.
• Origins: Northern Hemisphere (North America and Europe).
• The Scale: The National Wilding Conifer Control Programme estimates up to 7.5 million hectares are at risk of invasion, with a potential economic cost of NZD$4.6 billion due to impacts on primary production, biodiversity, hydro generation, and irrigation water storage.

Wilding infestations since 1900 based on spread and density estimates by DOC based on published and unpublished data. (Strategy, pg. 11, 2014) Source: Ministry for Primary Industries and licensed by MPI for re-use under the Creative Commons Attribution 4.0 International licence .

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How to Identify Wilding Pines

Wilding pines range from low, bushy multi-stemmed shrubs to towering timber trees over 40 metres tall.

Feature	Identification Details
Foliage	Evergreen, needle-like leaves attached to woody twigs, arranged in clusters of 2, 3, or 5 (depending on the species).
Cones & Seeds	Hard, woody cones housing light, winged seeds designed to drift several kilometres downwind.
Growth Forms	Ranges from dense, low-growing shrubs (P. mugo) to massive, upright forest trees (Pseudotsuga menziesii).

🛑 Caution Identification Note

Watch Out for our Native Pines! New Zealand native trees like Kahikatea (White Pine), Rimu (Red Pine), and Matai (Black Pine) are endemic podocarps, not exotic invasives. Always verify needle and growth structure before treating! (Norfolk Pine is also an exotic ornamental, not a wilding pine).

For additional image details of what to look for, check out our weed directory.

Choosing the Right Cut ‘n’ Paste Herbicide Gel

Field research shows that summer applications yield significantly higher kill rates than winter operations. Choose your gel based on species and surrounding environmental sensitivity:

Herbicide Safety Notice: Both MetGel and Picloram are soil residual (half-life of 5 days to 3 months) and can leach through soil moisture into non-target roots. Do not use them near waterways, desirable native plants, or prized trees. Use Bamboo Buster or Glimax for zero soil-residual risk, or where you are not sure.

Application Techniques: Step-by-Step

While tiny seedlings can be hand-pulled when the soil is damp, systematic herbicide treatment is essential for complete kill rates on saplings and mature trees.

Method 1: Cut Stump (Saplings & Small-to-Medium Trees)

MPI has released a ‘Cut Stump’ guide here.

1. Cut Low: Cut the tree as close to the ground as possible using loppers, a hand saw, or a chainsaw.
2. Cut Below All Green Foliage: Crucial step! Ensure your cut is below every single green needle and branch. Any foliage left underneath the cut line will allow the stump to resprout.
3. Paste Immediately: Within 15 seconds of making the cut, apply your chosen Cut ‘n’ Paste gel liberally across the entire freshly cut stump surface to draw herbicide straight into the root system.

Method 2: Drill & Inject / Frilling (Large Standing Trees)

For trees too large or hazardous to fell manually:

1. Drill or Axe Notch: Drill downward-sloping holes spaced 8–10 cm apart around the trunk’s circumference, or create deep, ringbarking axe cuts (frilling) through the bark into the active sapwood.
2. Fill Immediately: Fill the drilled holes or coat the fresh axe cuts thoroughly with Cut ‘n’ Paste gel. The vascular system will translocate the herbicide throughout the tree, killing it standing without heavy equipment.

Long-Term Management & Follow-Up Strategy

Wilding control is an ongoing commitment. Stopping re-infestation requires a strategic multi-year plan:

• Target Upwind “Takeoffs” First: Prioritise seed-bearing parent trees upwind or at high elevations. Stopping windborne seed distribution prevents cleared land from being constantly re-contaminated.
• 3 to 6 Months Post-Treatment: Inspect standing treated trees for needle browning and yellowing. Re-apply gel to any missed stems or green regrowth on cut stumps.
• 12 Months (Annual Spring Sweep): Walk the cleared site every spring or early summer to hand-pull new wind-blown seedlings while roots are shallow.
• 3 to 5 Year Maintenance Schedule: Wilding pines take 5 to 8 years to reach seed-bearing maturity. Carrying out a thorough site sweep every 3 to 5 years guarantees no new sapling will ever mature enough to release cones.

Always wear appropriate PPE, follow product labels carefully, and consult local authority or GROWSAFE requirements when applying herbicides commercially.

More Information

For the full details of what to look for, check out our weed directory.

Reference & Further Reading Links (external)

• National Wilding Conifer Control Programme (Biosecurity NZ / MPI) Official home of NZ’s national eradication strategy, offering comprehensive background on economic impacts, ecological threats, and regional management initiatives.
• National Wilding Pines Good Practice Guides Includes detailed operational standards for cut-stump treatment, ring-barking, and drill-and-inject methods across different species.
• Environment Canterbury (ECAN) Wilding Pine Handbook A practical landholder handbook combining regional pest management rules, species identification, and recommended herbicide choices.
• Wilding Pine Network NZ – Research & Field Studies Access to field trial data (including MBIE and Scion research) on species-specific herbicide effectiveness, soil residuals, and seasonal application timing.
• Weedbusters NZ: Wilding Pines Identification & Control Community biosecurity guidance for identifying specific pine species and applying safe cut-and-paste gel techniques around native bush and waterways.

Images reproduced with permission from https://www.weedbusters.org.nz/