Newsletter No. 9 April 2026

Posted on April 30, 2026

April has practically been and gone. The change in the season is being felt and the leaves are turning their autumn colours on for show. We have had a mix bag of weather across the country. April is a perfect time, if you haven’t already, thought about priority planting areas, identify number of trees (spacings) and ordering material.

Contacting your local Regional Council Land Management team is a great point of contact and wealth of knowledge. Check out our Nurseries page to see who is growing which cultivars.

NZPWRT has also prepared a media kit for the 2026-27 year, so if you are interested in advertising or promoting with us, please get in contact.

Value Proposition of Planting Poles

For many farmers, planting poplar and willow poles has always been “just something you do” on erosion prone land. But with increasing pressure on land use, regulation, and farm profitability, it’s worth revisiting exactly why these trees continue to stack up as one of the best investments on hill country.

It starts with protecting what you have already got - your natural capital or soil. It is your farms most valuable asset.

Once soil is lost in an erosion event, it can take decades to recover, normally to a maximum of 80% of what it was before. Poplar and willow poles act as a practical form of insurance, stabilising slopes and reducing the risk of large scale damage during heavy rain events.

Fast impact - one of key advantages of poplars and willows is how quickly they get to work. Poles establish rapidly and begin reinforcing soil within a relatively short timeframe. That makes them particularly valuable on high risk areas - gullies, slip prone faces and streambanks.

Work with the farming system - pole planting is designed to fit around your farm operation. Key features include:

wide spacing meaning you can continue grazing
deciduous trees allow light through in winter
stock benefit from the shade in summer
leaves can provide supplementary fodder in dry periods

In reality, you are not taking land out of production, but you are making it more resilient and often more productive.

We know that with pole planting that the risk is reduced. They limit the size and frequency of slips, protects infrastructure and able to recover faster after storm events.

Poplar and willow poles remain one of the most cost-effective and practical bioengineering tools available for hill country farming. They continue to prove their value year after year by protecting soil, managing risk and maintaining productivity.

They are a small investment now that helps avoid much bigger losses later.

36 year Wai-iti Trial

Wairarapa

A long running poplar trial in the Wairarapa is giving us some insight into what performs and what doesn’t on summer-dry hill country.

It was planted in 1988 on the Wai-iti farm near Whangaehu, Wairarapa where the annual rainfall is between 1100-1200 mm. The trial compared a wide range of poplar hybrids and commercial clones under real farm conditions. Some key take home messages:

poplar hybrids with P. trichocarpa or P. nigra handled dry conditions best
most hybrids will grow well - but clone choice still matters
risk of wind damage varies for the hybrids and the clones

Below is a snapshot of some of the results.

Box = middle 50% of the data
Line in the box = median
Whiskers = spread (minimum to maximum, excluding outliers)
Points = average

Tree survival - the P. deltoides x trichocarpa clones including ‘Wai-iti’ had 100% survival. Whilst P. deltoides x nigra had 80% survival with Veronese 100% survival.

The site was relatively windy, with higher stem breakage in P. deltoides x trichocarpa.clones, and some of the P. deltoides x nigra, P. deltoides x nigra x yunnanensis, and P. deltoides x yunnanesis clones. There was no stem breakage in P. maximowiczii x nigra clones.

Summary
The commercial poplar clones performed well, with good survival and growth over 30 years.

The poplar hybrids that were best adapted to the site were:

P. deltoides x trichocarpa
P. dettoides x nigra
P. maximowiczii x nigra

Dry condtions appeared to reduce the survival and growth of the poplar hybrids:

P. deltoides x yunnanensis
P. deltoides x nigra x yunnanensis
P. deltoides x maximowiczii

This trial reinforces that poplars remain a practical, long-term tool for erosion prone land, but getting the species and clone right makes a real difference. There is no single ‘best’ poplar - there is always a trade-off.

Explorer

It was great to be able to launch our four new Fit4Site App at the NZARM conference in Blenheim, November 2025.

Fit4Site is a site-assessment tool, designed to help farmers, landowners, nursery managers and advisers to evaluate what cultivar of poplar or willow to plant.

The aim is to empower evidence-based planting decisions, based on site attributes and needs of the tree. In doing this it also enables the user to gain knowledge and understanding.

Where to start?

download the QR code (if you don’t have Survey 123, can ‘open in browser’
you can ‘continue without signing in’
identify the key purpose(s) for the planting
identify where in the landscape they will be planted
identify site characteristic(s)
any pests to be concerned with?
is bee pollen relevant (if tick this you will get more willow selections)
suckering is generally only a concern if in an ungrazed environment
Cultivars will be given a ranking. Orange cultivars are those we have less research data on. The top 5-8 are what is most suited
We highly recommend that you check out the factsheets provided on cultivars before making a selection. This may also include talking to the local advisors at Council and checking if you are able to source material.
Having a number of cultivars in one selection is advised - this provides diversity, reduces risk and improves aesthetics.
If you want a report, provide your email and your selection will be sent to you

Busy being out in the field

February to April saw us hosting a number of workshops. With support from Te Uru Rākau, we hosted two two-day “Train the Trainer” workshops in Top of the South and

Tairāwhiti. These workshops bought together council staff, rural professionals and industry representatives. The focus was on equipping attendees with the skills and confidence to share knowledge with landowners and communities.

The first day centred on the science and practical application of poplar and willow planting. Sessions covered the role of these species play in erosion control, their unique root systems, and how they contribute to wider land and river management outcomes. Participants also explored recent research and trials, helping bridge the gap between science and on-farm practice.

Practical guidance on cultivar selection, tree placement, and long-term management. Discussions also extended to future opportunities, including forestry options and implications for the Emissions Trading Scheme (ETS).

Day two took participants out of the classroom and into the landscape. As part of this we visited local pole nurseries, a farmer where we got to see poplar and willows in practice. In Marlborough we visited a willow trial site beside the Wairau River and in Tairāwhiti, there was a form pruning demonstration.

Below is a form pruning demonstration video…

Figure 1: Group at Old Renwick Nursery, Blenheim

Figure 2: Famers property planted in Veronese

Figure 3: On farm at Tiniroto with 10 year old plantings

Figure 4: In the GDC nursery

These field based insights reinforced the importance of selecting the right tree for the right place, alongside planting on erosion prone land.

The workshop highlighted the value of collaboration between councils, researchers, and the farming community. By building a network of trained practitioners, they can share their learnings with others around the adoption of proven erosion control methods across the region.

Tairawhiti Poplar Demonstration Site

In 2025, there were some demonstration sites established in Tairāwhiti, thanks to local enthusiast and NZFFA member Kees Weytmans. These are at:

Pourau Inc near Hikuwai
Rere - near Rere waterfall and telephone exchange
Knapdale Eco Lodge

Cultivars used were Crowsnest, Veronese, Kawa, Geyles, Rotorangi, Shinsei, Fraser, Weraiti, Kaimai, Androscoggin and San Rosa

Kees showing the demonstration signage at Hikuwai

Rere demonstration site

Showcasing… Cheltenham (willow)

‘Cheltenham’ is a Salix matsudana x alba hybrid, released recently. It is a narrow-crowned willow with upright branching and a straight stem. It is male and has non-brittle branches and has non-bitter leaves. It is resistent to Melampsora coleosporioides leave rust fungi.

‘Cheltenham’ hasenarrow, lanceolate shapped leaves with a dark green upper and whiteish green lower surface. The midrib is green.

‘Cheltenham’ can be used for soil conservation, in riparian situations and river berm land. At age 15 years, it had a crown witdth of 9m. To read more see the Factsheet.

Pole Sleeve Audit - Northland

John Ballinger (Northland Regional Council)

A field audit was conducted 18-20 months after installation of Dynex, KBC and Wool pole sleeves near Okaihau. Sleeves were installed in winter 2024.

Key Results:

Farmers reported:

Woollen sleeves slipped because staples were too short
Wool became waterlogged, increasing weight, causing collapse or tearing
Wool lacked stiffness to stay upright when wet
Possums climbed the wool sleeves, contributing to failure
Where sleeves failed, ringbarking occurred on young poles.

Dynex and KBC sleeves provided reliable, long-lasting protection under Northland hill country conditions. Wool sleeves offer environmental benefits but are not suited to grazed or high rainfall sites without design improvements and full stock exclusion.

Note: Trials have also been run in Horizons and Greater Wellington regions as well with similar outcomes.