Six years of transformation at Staffordshire's Trentham Estate - one of the largest garden renovations of the decade - were rewarded in September with the European Garden Award, presented by the Germany-based European Garden Heritage Network (EGHN).
EGHN project manager Christian Grussen says: "Trentham is one of the most successful urban regeneration projects in the UK and one of the best examples in Europe for a garden contributing to, or even starting, this regeneration. It's a rare combination of innovative commercial enterprise, environmental enhancement and job creation."
While contemporary restorations of historic landscapes are not unusual, what makes Trentham so unique is both the scale of the £100m project and the fact that it is entirely financed privately, by developer St Modwen Properties.
Garden designer Tom Stuart-Smith has been involved at the site for more than ten years. "It was an extraordinary act of faith on St Modwen's part," he says. "You need the right person and fortunately its chairman Anthony Glossop, who masterminded the project, is an enthusiastic gardener."
The estate's gardens manager Michael Walker has also been involved since the start of work on the ground. He was previously head gardener at Waddeston Manor, another sumptuous estate in private hands that has undergone a modern makeover.
"St Modwen had owned the site for seven years before work on the grounds could begin in earnest," says Walker. "The time was all taken up with gaining planning permission and it even went to a public enquiry. It must have been hugely frustrating. But there was a lot of local support - there's a great sense of loyalty to the place.
"There was also a colossal amount of research done into the estate first. We had to understand and respect its past before going on with its future. It was important to get these people like Tom, Land Use Consultants and Liz Banks Associates in at an early stage because horticulture was key to the whole thing." An ecologist was also brought in to look at the woodlands because they are a site of special scientific interest.
Walker says of the EGHN award: "It was for the whole approach - it had to work as a business, be sustainable, as well as the horticulture. (The panel) takes a holistic view."
The site's commercial sustainability is ensured by the range of retail and leisure facilities that have been developed in conjunction with the garden, including one of the country's largest garden centres, run by Blue Diamond. "St Modwen is a property developer with a broad portfolio, though the shopping village is the sort of thing it has more experience of," says Walker.
"It has had to call on a great deal of expertise and dig deep into its own pockets yet has brought the project in right on budget, without any shortcuts or compromises. They really want to see it work."
Work at the estate is ongoing, though it reopened to the public six years ago - "as soon as it was safe", says Walker, even at a time when up to 100 contractors could be working on site on any given day.
The centrepiece remains Stuart-Smith's vast Italian garden, on the site of Charles Barry's Victorian parterre. Drifts of Miscanthus and Pennisetum billow amid fountains, sculptures, topiary and fastigiated Italian yew, which were used in Charles Barry's original design to mimic Italian cypresses. "The scale of everything is gargantuan," Stuart-Smith says. "You have to make it something extraordinary. You could spend £1m and get only one trick, but it's better to have a more immersive quality."
A more recent addition is Piet Oudolf's design for a challenging 3ha expanse between the parterre and the Trent, beyond which lies the retail area, where planting was completed in 2008. "We felt there shouldn't be just one designer," says Stuart-Smith. "We thought: 'Who is the most exciting designer around?', and that's what brought us to Piet."
According to Oudolf: "I came up with the idea of clipped hedging but that was too flat. It had to be something more intimate, even mystical, something to walk around rather than look across. And it had to withstand the occasional flooding of the Trent. But I think now it's a success."
Walker describes the Oudolf garden as "the icing on the cake", but adds: "He put forward a very complicated list of plants, some of which were hard to find. The bid went out to tender, but it wasn't all available in one go." These included the ornamental grass Molinia varieties 'Edith Dudszus' and the taller 'Heidebraut', interspersed with colourful splashes of Persicaria, Astilbe and Iris, and leading on to a taller perennial meadow that Oudolf describes as having a pattern like the neck of a giraffe.
The two designers' contributions "have used a similar range of plants, but in different ways", says Walker. "Both involve movement and migration - that's part of the flow of the schemes." Around Oudolf's "floral labyrinth" are viewing mounds that Walker is trying to encourage visitors to climb. "It's important to engage people who don't have a keen interest in plants," he says.
This philosophy appears to be paying off, as visitor numbers have grown steadily from around 100,000 two years ago to more than 300,000 this year. "The target audience is broader than for a National Trust or RHS garden, and that means catering for a broader range of interests," says Walker.
For young families, an area beyond the Italian garden now includes a soft tarmac track for pedal cars sponsored by nearby JCB, a maze of beech with integrated speaker points and a zip wire in addition to a regular playground. Another attraction is a barefoot walk - an idea borrowed from Germany - where children (and grown-ups) take off their shoes and socks and walk a circuit of nearly a kilometre over a range of surfaces and sensations.
"We feel it's important not to wrap visitors in cotton wool," says Walker, pointing out that forest skills such as fire lighting are also taught to children in the wider woodland and a planned ice rink on the lake is expected to attract 20,000 visitors.
The site of a former caravan park overlooking the lake is now occupied by a glass-fronted tea room and areas that were under tarmac or gravel, or occupied by functional buildings, have been greened up again. Allotments, run by a local society, are a further innovation implemented this year that will "double in size" in 2011.
However the regeneration has not been without its difficulties. "Vast swathes" of the ubiquitous invasives Rhododendron ponticum, Himalayan balsam and Japanese knotweed have had to be removed from the site, while fallow deer numbers have been controlled to promote regeneration of the woodland. Clearing areas of pine and larch plantation has also proved expensive. The trees "cost more to fell than their value as timber", says Walker.
He has what he describes as a "very small" team of nine full-time staff looking after the garden, with a further three on the wider estate, as well as 30 regular volunteers. "It's unusual to have so many (volunteers) on a private estate - I think that demonstrates the level of local interest," he says. "We had a lot of applications to work here, but it was hard to attract experienced gardeners and we are extremely fortunate to have the team that we do, some of whom we have trained ourselves. And of course we have always had students supporting the full-time team."
He aims for a light touch when maintaining the gardens, feeding only the 130 varieties of bearded iris in the upper garden and using low-nutrient mulches. "We don't want Piet's plants to get unnaturally tall - as they are they don't need staking," he says. "The only chemical we use is some glyphosate on the paths, which are steel-edged gravel, along with weed-burners."
Some tasks such as hoeing have been contracted out locally where cost-effective to do so. "We target our experienced resources where they are really required, such as dividing and replanting the perennials," says Walker. "Maintaining Piet's garden requires input from someone who understands it, who can ensure plants are true to type and spot when they are struggling. We have been lucky in having people who appreciate what he was trying to achieve. But you can never take your eye off the ball."
Looking to the future, he adds: "The board continues to support the garden's growth and development. There will be opportunities here for other designers in future - it's a big estate and needs good ideas to keep the momentum going. We have only scraped the surface of what's possible."