Heavier silt and clay based turf proves a success at the Millennium Stadium

A 'portable' pitch for a demanding international sport throws up many challenges for the Head Goundsman at the Millennium Stadium. Penny Comerford finds out how a new approach brought them through a highly successful last season

Cardiff's iconic Millennium Stadium, home of Welsh Rugby, came under public scrutiny once more during the Olympics when it hosted a quarter final in the football tournament, exposing the iconic stadium to a huge worldwide audience.

The Welsh rugby game went through a purple patch this season, thanks to the national team landing the Grand Slam after a successful Six Nations campaign in 2012. The Millennium Stadium provided a magnificent backdrop to some of those matches, and the excellent state of the turf did not go unnoticed by commentators and teams.

Several months on from its high pressure winter, Wales No 10, Rhys Priestland, was still able to judge it as 'superb' after several hours' pre-Australia summer tour kicking practice - training which always requires a decent surface underfoot. "We don't often get players commenting on the pitch," said Millennium Stadium Head Groundsman, Lee Evans, "but this team said it was the best stadium pitch they had played on."

It was not always the case in Cardiff. The stadium turf is unique in that it is grown on removable pallets under a closable roof. The sandy turf drained well, but cut up badly off the edges. In the early days, the grass looked sparse, the grid pattern of the pallets was obvious and the television image it provided was not the best. However, in the hands of Lee and his team, using local knowledge and getting to understand the drainage rates of the sand-based soil, the turf improved, but it wasn't an easy job.

This past season, turf maintenance company Ecosolve has had an input into the presentation of the pitch with its unique Drill n Fill aerator. The pressures of the international sport obliged Lee Evans to employ a different turf management system last autumn, when playing commitments and public usage demanded he swapped the sand-based soil to a heavier one, despite its inherent poorer drainage.

Traditionally, the palletised pitch is changed twice a year and Lee was just about to do it last autumn when the Welsh Rugby bosses asked him to hold fire. Wales had been doing so well in New Zealand, that they wanted the Rugby World Cup quarter and semi finals to be shown live on giant screens to the adoring public sitting in the Millennium Stadium. This duly took place, but meant that time to establish the new pitch for the Wales and Australia game on December 5th was really tight.

"The traditional sand-based turf would not have produced the correct results in the time available," said Lee, "so we opted for a heavier silt and clay-based turf which we knew would grow well and produce the surface stability required, but would not drain sufficiently." The Drill n Fill aerator had been successfully trialed in April 2010 and was the obvious answer to improve drainage.

Two days after the match, Ecosolve went into the stadium with a team of four machines fitted with custom-made drills and depth limiters to accommodate the pallets. A bespoke blend of sand and zeolite was used for the backfill, designed to enhance infiltration and percolation rates. "Afterwards, we topdressed and overseeded and the resulting turf was excellent," Lee reported. He plans to repeat the exercise this coming season.

"It's the only stadium in the UK which has to use turf, as opposed to other stadia that can establish their surfaces from seed," explained Lee. "The pallets have to be changed twice a year and we don't have time for seed to take." The pallets of turf are taken in and out to allow for other events, which can range from motor and equestrian sport to a massive charity dinner.

Management of the roof is also crucial. "We can't grow grass in the dark," said Lee, "but we can prevent some of the heaviest rainfall landing on the pitch - it is a delicate balancing act experienced by very few British groundstaff."

However, the versatility of the system and the stadium has not gone unnoticed. The French Rugby Federation are said to be building their new stadium at Orly based on the Millennium and, last year, the Cardiff venue won a BSI award for sustainability due in part to the palletised pitch which allows reuse of the rootzone.

The Drill n Filled turf was challenged several times during the past rugby season, and came through with flying colours. "By the time we came to the Wales v France game, we were fielding one of the best surfaces in the tournament, thanks to the combination of the heavier turf with the action of the Drill n Fill," he said. The treatment allowed surface water to rapidly percolate down through the 125mm deep rootzone.

It was a fortuitous combination, all the more because during the final Six Nations fixture last February, the French insisted on the Stadium roof being open. "One hour before kick-off, the heavens opened and John Inverdale was doing a live feed for the BBC in a tempest," Lee recalled. He was worried momentarily, but "it drained like a dream, thanks to the specialist work undertaken."

That Wales went on to win the match and the Grand Slam was almost an incidental!