Newsletter No. 5 March 2025

Posted on March 21, 2025

Wow! 2025 seems to be racing along, as we head into autumn. Some parts of the country are starting to certainly feel the effects of the dry.

While it might be hard to contemplate, this is a great time of year to think about your winter planting programme. Think about what needs planting, what material you need and getting pole orders in with your local regional council.

Technical Advisory Group (TAG)

The TAG plays a vital role in NZPWRTs process, serving as our link to and from our supporting councils. Recently, they met in Palmerston North to brainstorm what research and development for the Trust over the next 5-10 years.

The group is chaired by Melissa MacDougall, with participants nominated by their respective councils to represent both river and land management. As frontline professionals, they provide valuable suggestions and guidance to the Trust. They also serve as a crucial channel for the Trust to share information back with stakeholders.

The TAG is working closely with Trevor Jones, Plant & Food Research, and NZPWRT to develop this strategy, which will help guide the Trust’s work. It is expected to be completed by May 2025, and we will keep you informed of the outcome.

Some of the TAG members: Dave Sharp (TRC), Weston Brown (Horizons), Keith Finalyson (Environment Southland), Chris Vicars (TRC), Adrian Jepson (WRC), Mike Jensen (GW), Trevor Jones (PFR) and Melissa MacDougall (GW)

After the meeting, the group visited the nursery, where PFR trials new varieties as part of the breeding plan, and manages the Trust’s germplasm.

Ambassadors out in the field

by Kate Taylor

Wise use of poplars and willows was evident at a recent field day at our NZPWRT ambassador James Hunter.

The Hawke's Bay Farm Forestry field day – third time lucky due to weather postponements – was held to belatedly celebrate James winning the North Island Farm Forester of the Year win back in 2022.

Rangitoto has been in the Hunter family continuously since1856. James is the 5th generation to farm here returning to work on the farm for his father in 1989 and taking up the lease from his family trust in 1996.

It is 668 hectares, or 550ha effective, increasing to 565ha as pines are harvested. It has 54ha under QEII National Trust covenants, 19ha of wetlands and dams, and 170ha improved through artificial drainage.

“Every small piece added together forms a great picture, and that’s just on this farm. Multiply that on every other farm and it’s all part of the whole picture,” James said on the day.

HBFFA president Tim Forde, who is also a NZPWRT trustee, said the property was a “fantastic whole farm package” with a highly productive and profitable farming business incorporated with a landscape protecting and restoring valuable indigenous remnant vegetation, waterways and woodlots of potentially valuable timber species.

The field day convoy stopped at the site of a recent logging operation, where change of land use, poplar for timber, registering exotic forests in the ETS, and management of older poplars and willows formed part of the discussion.

James talked about how the soil carbon measurements were similar under the pine trees and the poplars, but the carbon was “vaporising” from the bare ground where the trees had been harvested.

Tim Forde also talked about the many uses and benefits of poplar timber, and fellow trustee Stan Braaksma talked about the management of poplars and willows and the need to use new varieties as research and trials were constantly improving their form and function.

Unfortunately, slight rain (again) meant most of the convoy did not trek to the back of the farm to see the 4ha totara plantation, and established QEII block and wetland restoration project.

James Hunter talking about his planting, flanked by some of his poplar and willow plantings

Pollarding Poplar and Willow

With many parts of New Zealand experiencing drought, poplar and willow trees often stand out as the only green on the landscape. By pollarding these trees now, you can unlock several key benefits for your farm.

Why Pollard Now?

✅ High-Quality Fodder for Livestock

Poplar and willow leaves are 65-70% digestible, similar to lucerne hay.
They contain 15% crude protein, exceeding livestock maintenance needs.
Leaves also include beneficial compounds like condensed tannins (CT) and phenolic glycosides (similar to aspirin), which support animal health.

✅ Tree Maintenance & Longevity

Reducing canopy weight helps prevent tree damage and maintains structure.
Both poplars and willows thrive when pollarded every 3-4 years.
Leave some full-canopy trees in rotation to provide shade and maintain root stability.

Safety First

When pollarding, always prioritise safety. Use appropriate equipment and techniques to minimise risk.

Learn More

Our website has detailed guides on pollarding, tree health, and best management practices. Use the search button to explore, or start with these helpful links:

Workshops

We have held or participated in several workshops in 2025, including a Bioengineering Tools workshop in Napier, an Understanding Poplar and Willow workshop in Whakatāne, and a presentation at the Nukuhou Catchment in the Bay of Plenty. The main theme has been to highlight the strength of poplar and willow for erosion control and streambank stabilization.

Although attendance has been lower than anticipated, the discussions, learning, and participation have been excellent.

Topics covered included the role of willow as a bioengineering tool in our river systems and its contribution to protecting communities, the selection of traits in our breeding program leading to field trial sites, and how to identify trees in the field using the NZPWRT identification key.

Learning about the extensive root systems of both poplar and willow and how they function in their respective environments. It is well known that their root systems are highly developed. The diagram below illustrates a nine-year-old poplar with roots weighing 17.9 kg and extending a total of 663.5 meters.

If you’re interested in learning more about poplar and willow—whether as a group of professionals, a catchment group, or a group of farmers—feel free to contact us at info@poplarandwillow.org.nz, and we’ll do our best to arrange something.

Ian McIvor talking to the Nukuhou Catchment Group

Ian talking to participants at the Whakatane workshop about tree ID in the field

Update on breeding work

Research and breeding work is contracted to Plant and Food Research, where Trevor Jones is the lead scientist. Updates of recent breeding includes:

Willow Crosses (2019 & 2021)

The 2019 and 2021 willow crosses included hybrids of tree and shrub willow species selected for specific traits:

Tree willow species:

Salix gooddingii × S. matsudana (drought tolerance & rough bark)
S. alba × S. gooddingii (leaf rust resistance)

Shrub willow species:

S. eriocephala, S. lasiolepis, S. reinii, S. tetrasperma (leaf rust resistance)
S. lasiolepis (drought tolerance & bitter leaves)

From the 2021 crosses, 31 seedlings with good growth, strong stem form, and leaf rust resistance were selected for propagation from stem cuttings.

From the 2019 crosses, five tree willow clones (S. matsudana × alba) with strong cutting propagation success were chosen for field trials.

Poplar Field Trials

A 12-year-old field trial on the berm of the Ashburton River berm showed:

The P. maximowiczii × trichocarpa and P. trichocarpa × nigra clones showed good growth. However, many P. maximowiczii × trichocarpa clones were susceptible to wind damage, leading to stem and branch breakage.

The P. trichocarpa × nigra clones had narrow crowns and light branching, making them less prone to wind damage. These clones have been released to regional council nurseries for further trials.

Manawatū Field Trials

A 37-year old field trial showed the following:

The P. deltoides × ciliata and P. deltoides × trichocarpa clones demonstrated good growth, though some were prone to wind damage.

One P. deltoides × ciliata clone showed strong growth, good stem form, and wind resistance, making it a potential candidate for wider planting.

The P. deltoides × trichocarpa clone ‘Pakai’ (NZ 5009) performed exceptionally well.

The ‘Eridano’ (PN 850), ‘Kawa’ (NZ 5006), and ‘Toa’ (NZ 5007) clones had good growth, though ‘Eridano’ and ‘Kawa’ exhibited poor stem form in trials.

A 35-year old gene pool stand showed:

The P. deltoides x cilata and (P. deltoides x nigra) x cilata clones showed good tree growth, but most of the clones did not have straight stems, and some were susceptible to wind damage.

One of the P. deltoides x cilata clones had good tree growth and stem form, and no wind damage, and could be suitable for wider planting.

Showcasing… Kawa (poplar)

‘Kawa’. bred in NZ in 1974, is a cross between P. deltoides and P. yunnanensis from China. It was released commercially in 1986.

‘Kawa’ leaves are heart-shaped, and green on the upper surface and pale grey-green below. The midrib and petiole are tinged pinkish red on the upper surface. The leaves remain on the tree for much longer and turn bright yellow before leaf fall. New leaf emerges late September.

‘Kawa’ favours moist areas that do not get excessive wind, and is not very frost tolerant. It is suitable for soil conservation, amenity purposes, firewood blocks and timber. ‘Kawa’ should be planted in sheltered sites such as valley floors, gullies and terraces. It is widely used in the western and norther regions of NZ. It has good possum resistance, and rust resistance in most situations. Kawa is one of the densest poplars at up to 360 kg per cubic meter, making it the leading timber producing poplar.

What’s coming up…

South Island Field days at Kirwee 26-28 March. Come and see us at site C70-71 in conjunction with NZFFA
Understanding Poplar and Willow Workshops in conjunction with NZARM, 2-3 April at Whanganui. Registrations
Nursery Managers Group, 7-8 April in Palmerston North
Mystery Creek Field days 11-14 June
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