Those challenges are at the forefront of work being carried out at Trentham Estate in Stoke-on-Trent. In 2014, head of garden and estate Michael Walker embarked on an ambitious programme to reveal the best of the landscape created by Lancelot "Capability" Brown while helping the site evolve and plan for the future.
The work at Trentham coincides with the Capability Brown festival that marks 300 years since Brown's birth. Trentham is an Urban Capability Brown 300 site, and was a key part of Brown's life work. He was commissioned to work there three times between 1759 and 1780, by the Duke and Duchess of Sutherland.
A 1759 map of Trentham by Capability Brown. Image: Staffordshire & Stoke-on-Trent Archive Service
Trentham's main vista is centred around a lake which Brown created by rerouting the River Trent, and linking the water with the park and woodland areas. But over the years the best vistas had been obscured by decades of Rhododendron ponticum and conifer growth. In the past two years, with the help of local contractors, the Forestry Commission and other bodies, around 80 per cent of the tree cover has been thinned, opening up those views Walker felt could be restored.
The resulting series of open spaces around the lake are now being planted to a series of schemes by Dr Nigel Dunnett, professor of planting design and vegetation technology at the University of Sheffield. Many of the designs use annual and perennial meadow mixes for which the landscape designer is famous thanks to his work at the London Olympics.
Dunnett is the latest in a long line of designers to make their mark on this landscape, from Charles Bridgeman before Brown's time, through to this century's perennial and Italian gardens by Piet Oudolf and Tom Stuart-Smith. The restoration plans aren't slavishly copying Brown's landscape or freezing Trentham in time; instead, the work will "restore the bones and add new flesh" to Brown's landscape while also respecting the complex history of the site, explained Walker (pictured below).
Michael Walker, head of gardens and estate at Trentham. Image: Supplied
Brown used the best of what his predecessors had created while recognising, for example, the value of the historic woodlands on the hill and linking them with his scheme by slicing a carriageway through their middle. But he also swept away much of the "contrived, formalised landscape" that had gone before.
"The scale of removal must have been incredible to have gone pretty much overnight from such a formal landscape," Walker said. He has managed to find a way to work on a scale that pays homage to Brown without needing a Brownian budget, by using cost-effective meadow seed mixes formulated for maximum colour and flowering time, as well as biodiversity.
Dunnett, supported by longtime collaborators The Landscape Agency, was first engaged in 2015 to create 10,000sq m of annual meadow, using his pictorial meadow mixes. That area (pictured below) was a huge hit with visitors last year, with 2015 seeing a record 545,000 visitors.
This year the meadows will more than double in size. Visitors will be led around the lake by a series of designed meadows and perennial plantings by Dunnett, including a new woodland garden with wetland glade, and a new remodelled entrance space to the gardens. Dunnett's approach will build on the naturalistic planting styles of Stuart-Smith and Oudolf that are already well established at Trentham, but take these forward in his characteristic dramatic and impressionistic style, with a strong emphasis on colour.
"The landscape has been touched by so many other people," Walker said. "It's about recognising that and enabling a landscape to continue to evolve, rather than saying "OK, we've got a very important Capability Brown landscape, full stop, so we're going to restore that ... The driving force hasn't just been to get back to Capability Brown, but to understand a very complex historical landscape."
The annual meadow at Trentham. Image: Nigel Dunnett
Many of the areas will start with annual meadows, either seeded or turfed, which will remain for several years before those schemes are relocated elsewhere. Those areas will be built up over time in layers, moving annuals into perennials and perennials into shrub and tree plantings.
Meadows offer a sustainable and cost-effective way of making a quick impact, Walker explained. Some of the meadow mixes will come from Pictorial Meadows, the company which Dunnett founded.
Jonathan Wild, commercial director at Pictorial Meadows, said Trentham is a "perfect template" for the company's seed mixes, many of which were originally formulated by Dunnett to create "sweeping and impressionistic" landscapes.
Pictorial Meadows' mixes offer long flowering production that goes from spring through to early frosts, in a succession of colours, and offers far more density of flowers than a typical wildflower meadow. Many of the mixes grow happily on fertile soil, making them relatively low maintenance.
The plan also recognises that "all planting is ephemeral to some extent" so it's important to plan for the future, when even the best-planned schemes no longer suit a site. There is no trace of perennial or bulb planting from Brown's time, if it existed at all; and even Oudolf and Stuart-Smith's plantings, a decade old, are requiring increasing amounts of maintenance to keep them in pristine condition.
As part of the festival, Trentham is focusing on the natural biodiversity of the Brownian landscape. The estate has embarked on a major ecological programme with help from Staffordshire Wildlife Trust, Natural England, English heritage, and the local council, resulting in the return of heathlands and other wildlife including otters. Part of the site is an SSSI and is in a 10-year Higher Level Stewardship agreement with Natural England.
Clearing the lakeside area in preparation for annual meadow planting. Image: Supplied
Not everything has been restored to Brown's time. Some wooded river edges have been retained in favour of wildlife, and the Staffordshire Wildlife Trust have also been helping with enhancing the value of the river and linking it to a wetland, a connection lost when Brown dammed the river to create the lake.
The twin threats of climate change and disease have been the biggest driver of the changes at Trentham; the festival has just helped spur that on, Walker explained.
The discovery of Phytopthera ramorum in the rhododendrons was timely, as it meant the Forestry Commission helped fund the £100,000 cost of cutting them down. The work has been done in partnership with local forestry contractors HRJ Gould, who Walker said have been "brilliant", enabling much additional revelation and conservation work.
Around 30,000 conifers - planted as commercial woodland - have been felled, including 10,000 just last winter, revealing the statue of the first Duke of Sutherland which tops Monument Hill. Dunnett will also work with Trentham on diverse tree and shrub choices to ensure they are resilient to climate change and disease.
"Our strategy has been in recent years - since Phytopthera and the threat of ash dieback - to diversify our monoculture of oaks on site," Walker explained. That doesn't mean creating "a spotty mix of trees with every tree and shrub under the sun; we need to retain the historic character of planting". Visitors are also a key consideration in the designs. Dunnett's work and the new tree plantings will improve the seasonal appeal of the site, adding spark in winter and early spring. Ultimately, "they will be beautiful mixes of planting," Walker said. "We are immensely proud of the planting at Trentham."
Planting Plans - Order of 60,000 new plants driving development of meadow, woodland and other areas
The planting plans at Trentham will take several years but 2016 will see plenty of new additions, with more than 60,000 new plants already ordered this year and many more in the pipeline. New plantings planned or underway include:
Sunny welcome - Visitors entering the gardens over the River Trent will be greeted by a colourful new Dunnett scheme of some 5,000 perennials. Key plants in the sunny, dry site include Achillea 'Terracotta', Achnatherum (formerly Stipa) calamagrostis, Leucanthemum x superbum 'T.E. Killin', as well as campanula, echinacea, geraniums, salvias, malva, scabious and Verbena bonariensis. Large numbers of grasses such as Deschampsia cespitosa 'Gold Veil' will also echo Piet Oudolf's nearby Rivers of Grass garden.
Woodland planting - Another 22,000 perennials are being planted in semi-shade on the opposite side of the lake this week. Dunnett's naturalistic design uses a series of mixes themed by colour, each containing some 20-odd species: a blue and white mix includes Helleborus 'Westerflisk' and Hesperis matronalis; a yellow and white mix includes such plants as Anemone nemorosa, Anthriscus 'Ravens wing' and Silene fimbriata; and the pink and white mix includes Chaerophyllum hirsutum rosaeum and Silene dioica. A North American mix uses Aster divaricatus and Dicentra eximia 'Alba', among dozens of other species. Long curving lines of ferns and grasses such as Dryopteris wallichiana and Carex 'Ice Dance' will segment the scheme, and groundcovers will include Cardamine pentaphylos and Galium odoratum.
All the plants have been sourced, except for the elusive Disporum 'Night Heron'; Walker is still searching for a supplier. Thousands more perennials will be planted across the pathway from this scheme in Autumn, making it a "fully immersive" planting.
More meadow - The original meadow area of some 10,000sq m to the North-West of the lake was a huge hit with visitors in 2015, when it was planted with a Pictorial Meadow mix. The meadow is now being doubled in size, and reseeded with three different meadow mixes that Dunnett used at the Olympics: 'Olympic Gold', 'Pastel' and a standard mix. Another massive meadow area is being sown stretching down the eastern side of the lake.
Wetland area - A cleared section of woodland on the water's edge offers the perfect spot for damp-loving plants such as ferns and astilbes.
Trees - Newly-planted saplings are visible around the estate, and more will be planted over the years, with a focus on extended seasonal colour.
Species such as Magnolia, Stewartia and Davidia will be planted in great swathes of a single variety for maximum impact. Walker hopes this will become a "unique selling point" at the estate.
Experimental areas - The work at Trentham is partly trial-and-error for the gardening team, but there are plenty of opportunities to test out ideas. One area at the south end of the lake offers a chance to test the best way to plant wildflowers: a natural mound of earth will be edged with meadow turf product for instant visitor impact, with the remainder of the spot sown with a bespoke annual seed mix.
Seasonal impact - Walker plans to add more winter and early spring colour wherever possible, through additions such as winter aconites, violets, cowslips and primroses, snowdrops. He also has an "aspirational" dream of planting a million bulbs around the lake.