The hi-tech — and very secret — turf coming to Te Kaha stadium

Monday, 19 May 2025

Rugby turf is sacred, of course, but construction managers at the Te Kaha stadium project will not let The Press see the new stadium’s grass as it grows off-site.

And they will not say why.

However, The Press was invited into One NZ Stadium to see where the turf will be unrolled later in the year after it was planted in March somewhere on the outskirts of the city.

Christchurch City Council’s turf specialist, Dr Richard Gibbs — who has worked on pitches in Fifa stadiums and been involved with every major stadium in New Zealand, and who has a PhD in soil science from Lincoln University — was also happy to talk.

“It's going to be the highest-tech field of play in the country,” Gibbs said.

That means some artificial grass and plenty of layers.

The first layer will be a polypropylene “carpet-backed hybrid turf system”, which has a thin base and several centimetres of green blades of fake grass.

Into this carpet have been layered sand, organic compost and dwarf perennial rye grass seed, which is commonly used in New Zealand and northern European stadiums.

This layer is being carefully tended to ensure uniform growth at the secret location.

When the time is right, the grass and system will be rolled and transported to One NZ Stadium.

The ground there will have been prepared into more layers.

The base layer will not be concrete or asphalt, but levelled and compacted dirt and rock.

On top of that goes a “vacuum and ventilation system” that allows groundskeepers to move air to “provide a good growing environment” in the otherwise windless stadium, said Gibbs.

Likewise, the stadium’s roof, currently being installed, will prevent rain, and many irrigation sprinklers under the turf will provide the water to keep the grass growing.

Above the pipework will be 150mm of gravel drainage and above that 300mm of growing medium, including the turf grown off-site.

All of the layers add up to 450mm of depth. About 5% of the turf will be artificial.

“The players and people on the field will experience an essentially natural grass surface,” said Kent Summerfield, project director of One NZ Stadium.

Except, there will be no mud.

Once installed, the turf will be hand-mown about every other day, depending on the event schedule. “It’s like a golf green in that respect,” said Gibbs.

From about April to September, grow lights will be wheeled onto the turf to provide enough light for photosynthesis. In northern Europe this can happen daily, Gibbs said.

When concerts or other non-sporting events are scheduled, large “tiles” will be brought out to protect the turf from the extra crowds.

If a stage remains for a week, the grass beneath may die. When that happens, new turf growing off-site will be installed, said Gibbs. Equally, sports will damage the turf and repairs will be needed.

Installation of the pitch will start late this year, ahead of the projected opening in April 2026 and providing nothing amiss happens to the grass.

Weirder things have happened to city’s sports facilities.

In 2018, an athletics track at Ngā Puna Wai sports hub in Wigram was damaged by late-night vandals, which delayed the opening of the athletics track for several months.

And in a previously undisclosed incident, protesters sprayed an unknown chemical onto a grass outfield at Hagley Oval in March 2022.

They spelled the the words “No mandates” and “Freedom”, said the council’s head of parks Rupert Bool. The grass had to be replaced.