Ten years in the making, the National Arboretum Canberra, by Taylor Cullity Lethlean with Tonkin Zulaikha Greer Architects, is a grand dream realized – and unfolding – writes Philip Thalis, for Landscape Architecture Australia 138.
In 2003 disastrous bushfires flashed across south-west Canberra. Among other acts of destruction, they burned out a large area of plantation pine and created a 250-hectare void. Cleared of forest, a scene of dramatically undulating topography was revealed: an outlook down the long dimension of Lake Burley Griffin and framed views of Black Mountain to the north with Civic in the middle distance, Yarralumla and Red Hill directly in the foreground and Scrivener Dam and Mount Stromlo to the south, with the Brindabellas beyond. The site was available to be claimed by a project of matching significance: the National Arboretum Canberra.
The renewal of such a major site presented symbolic opportunities – what was destroyed by nature’s savagery could be healed by enlightened ecological strategies. One of the declared aims of the project was to protect the tenuous survival of plant species in a climatically challenged world.
With foresight, the Australian Capital Territory Government launched a two-stage national competition in September 2004 and the outcome of the second stage was announced on 31 May 2005. The winners were landscape architects Taylor Cullity Lethlean (TCL) and Tonkin Zulaikha Greer Architects (TZG), fine established practices working in close association. Their design concept was expressed as “100 Forests/100 Gardens.” The result is an all too rare recent example in Australia of a successfully realized project arising from an open competition-winning scheme.
An arboretum, a term first coined by John Claudius Loudon in 1833, is a collection of trees and shrubs established for display, study and research. Such practices have a long history dating back to ancient times. Distinct from agricultural practices, an arboretum can be effectively understood as a tree zoo.
The selection of this site allowed the new arboretum to relate to Canberra’s existing Lindsay Pryor National Arboretum on the shore of the lake. It also relates more generally to early Canberra’s evocative traditions of test plantings by Marion Mahony Griffin and Walter Burley Griffin and the horticulturist (Thomas) Charles Weston. Weston’s approach remains in sombre evidence in major landscape spaces such as Haig Park, City Hill and remnant groves around Yarralumla.
TCL and TZG’s competition scheme developed the idea of 100 Forests/100 Gardens as a comprehensive site strategy embracing ideals of “sustainability, biodiversity and public environmental concern [that encompasses] a program, and an on-going event, not a design chiefly based on aesthetics” (executive summary, second stage competition submission).
The forests conserve and display one hundred botanical species. Two existing mature groves of Himalayan cedar and cork oak are incorporated, which provide a glimpse forward to the eventual maturity of the forests. The trees were selected on strict criteria, including rarity, degree of environmental threat to the species, country of origin, temperate sources, whether they are suitable for Canberra’s climate, distinctiveness and diversity. Among the many fascinating species chosen, visually spectacular specimens include the dragon tree, the purple-leaved smoke bush and the giant sequoia. There is an abundance of conifers, including monkey puzzle, bunya, Turkish, Aleppo and stone pines, even Radiata. The pin oak, that emblematic cultivar that so typifies Canberra’s autumn, is rightly celebrated. The arboretum will also act as a seed bank for the selected species.
Interspersed amongst the forests are secret gardens, which will flourish into places of surprise and delight. The massed plantings are augmented by a burgeoning collection of individual trees, gifted by other nations and dignitaries. Sculpture has been deployed at strategic points and the whole site can accommodate an evolving art program.
Founded on a simple but decisive geometry, the project has a flexible “tartan” grid plan that overlays the site and is set out in parallel to Griffin’s water axis. The grid is organized in bands of forests, large enough for an immersive experience of each species. The forests are defined by fifteen-metre-wide open grassland allées that lead towards the lake, with smaller, randomly spaced cross allées.
The dominant grid is overlaid by a range of contrasting elements, recalling somewhat Bernard Tschumi’s scheme for Parc de la Villette, but less dictated by rhetoric. These elements, each with its particular logic, include serpentine paths and roads that work with the contours as they traverse the grid in a free manner, like Broadway’s meander through Manhattan’s matrix. The topographic elements are celebrated – hills are marked by lookouts and artworks, while the valley is dammed to form a 37.2-megalitre lake.
The site entry leads straight into a sequence of the arboretum’s most dramatic features. Off a utilitarian grade-separated intersection from Tuggeranong Parkway, an underpass frames the grand sweep of curving terraces that scissor up to the main terrace. The entry road follows the outer edge of the sweep, progressively bringing into view the Events Terrace, which combines boldly scaled architectural and landscape elements. The Events Terrace is sited to anchor the centre of the arboretum and to form a powerful relationship with Canberra’s civic landscape. It has an imposing scale rarely attempted in either Australian landscape design or city-making projects.
Forming the arboretum’s monumental heart, the Events Terrace comprises a large grassed amphitheatre that unites two architectural structures. The buildings, linked by contour and material palette, display a contrasting form, scale and structure. In the manner of the placement of ancient Greek temples, they occupy prominent spurs below the main ridge. This emphasizes their three-dimensional form, as they can be seen from below and above and in direct elevation from multiple points across the valley. The amphitheatre, the buildings and their terraces provide magnificent volumes, great public indoor and outdoor rooms, with stunning panoramic vistas back to central Canberra.
Particularly impressive is the Visitor Centre, the site’s major building. It is entered through a gabion-lined cutting from the terraced car park behind and its broad curving roof defines a space of remarkable grandeur. The fan-shaped, timber-framed structure sits on a concrete plinth, opening onto an expansive terrace to the east, while to the west are service spaces, a bonsai garden and sheltered seating areas. The Visitor Centre also accommodates a cafe, meeting rooms, site administration and retail spaces. It is sure to become a major drawcard for functions. The smaller room is more singular in form, with a prow roof aligned towards Lake Burley Griffin and Russell. The generously scaled, grassed amphitheatre is also certain to become the venue for many memorable performances.
Pragmatic elements are incorporated in a straightforward way. The main car and coach parking is rationally organized to the rear of the Visitor Centre. Local parking areas are distributed throughout. As well as the dam, other water-harvesting strategies include harvesting swales, irrigation systems connected to a bore and large storage and irrigation tanks.
The intelligent use of the grid as the primary structuring element challenges a number of tropes of contemporary Australian landscape design and indeed the city’s form. It opposes the ideologies and resultant geometries that have come to typify Canberra: the Griffins’ carefully interwoven triangles, hexagons and axes; the postwar technocratic picturesque, as deadeningly applied by the surveyor and traffic engineer; or the wilfulness of the dominant Gardenesque movement. Consider the parallels with Gardenesque’s fellow traveller Townscape, so forcefully denounced by Colin Rowe and Fred Koetter for its “tendency … to provide sensation without plan, to appeal to the eye and not the mind, and while usefully sponsoring a perceptual world, to devalue a world of concepts.” (Collage City, 1978, page 36.)
The straight line of the grid reveals the topography like a cross-section, a transect, accentuating the perception and experience of the slope. Reflect on how integral and memorable are San Francisco’s grid of dramatically framed streets; Jaipur’s nine-square plan, shifted for the hill and to accommodate the palace; and Miletus’s three different grids on the upper slopes, framing the public places on the flat. The grid plan’s relation to site and slope has long been one of landscape’s and urbanism’s most potent moves. The grid runs counter to contour-driven schemes, heightening the sense of the topography.
The arboretum’s plan confidently proposes many fruitful avenues for the layout of large landscapes, and by extrapolation the city itself. Recall the great seventeenth-century French landscape traditions, which informed city making over subsequent centuries. Marc-Antoine Laugier, in [Essai sur l’Architecture in 1753], set out ideas on how landscape design could inform urban design:
“Anyone who knows how to design a park properly, will have no difficulty designing the plan by which a city will be built in terms of its area and location. Squares, intersections and streets are needed. Regularity and strangeness are needed, correspondences and antitheses, accidents that vary the picture, great order to the details, but confusion, clashing and tumult in the whole.” (Günther Vogt, Miniature and Panorama: Vogt Landscape Architects, Projects 2000–12, Lars Müller Publishers, 2012, page 529.)
TCL and TZG forcefully stated in their second-stage competition submission, “100 Forests/100 Gardens will be a platform of substance for hundreds of years of growth.” The plan is the foundation, but the place will be subject to a living process, open to evolution, maturation and enrichment.
Beyond its bounds lie the future challenges of how the National Arboretum will make itself part of greater Canberra, not just an occasional drive-to destination. This will involve taming Tuggeranong Parkway (already suggested by the three grids that traverse the parkway) and the sprawling tentacles of its catastrophic interchange with William Hovell and Caswell Drives nearby. Such redesign would allow better connections with nearby public assets, including the lakefront, the existing arboretum, Lady Denman Drive and Scrivener Dam. In time and as the place becomes part of the city’s daily life rather than a place apart, the project’s urban presence may well lead to positive change beyond its boundaries. The mooted suburb of Molonglo to the immediate west could also provide a more local street edge address and welcome quotidian uses to animate the place.
The National Arboretum is a work of rare ambition and exceptional scale in Australia. This is a mature project, confident in its architectural and landscape agendas and expression. It is a fabulous addition to Canberra’s legion of public assets and speaks optimistically to the future of Australia’s public places.
Chris Johnstone, TCL project landscape architect…
“The National Arboretum Canberra is one of those ‘utopian’ landscape projects which very rarely present themselves during a career. A vision; a clear and robust design response; a committed client who understands, supports and facilitates the design through every stage; a tenacious quorum of people who know how to work with a site to realize the project on the ground; and a timeframe that allows this combination to refine and grow. This project has been an unforgettable and life-changing journey for me.
Through the process of working on the NAC project over the past eight years, threads and relationships that will continue to grow and evolve have been realized, allowing the project to speak with a multitude of voices on topics such as conservation, design, urban development, climate change, arboriculture, silviculture, horticulture, preservation, biodiversity, recreation, memorialization, art, culture, politics, nationalism, geography, environment, evolution, aesthetics and my favourite, temporal change. This change is seen in the time it will take for the forty thousand trees to grow and dominate the 250-hectare site across a one-hundred-metre level change; the time it will take for each of the forests to create an immersive experience with a single species of tree; the time it will take for the arboretum to grow and evolve with the people and city of Canberra; and the time we will have to watch, walk and feel this happen.
‘If you think in terms of a year, plant a seed; if in terms of ten years, plant trees; if in terms of one hundred years, teach the people.’ – Confucius.”
Simone Blis, TCL senior landscape architect…
“The National Arboretum’s playspace project began in January 2011. Its purpose is to act as an intrinsic play element that connects an iconic playground project to its forest home. The playspace project is not dissimilar to a cat – it really did have nine lives, surviving many potentially dangerous events, including a change in the client team, delays in tender and a significant value management exercise. But it’s now underway, and it’s going to be magnificent.
My role within this process has been that of mediator, accountant, advocate, curator and ornithologist. Never did I think I’d be studying the behavioural patterns of cockatoos, just in case they visit Canberra to chew on some cedar-clad, acorn-shaped treehouses. Design and ongoing construction of the project requires a circus of coordination involving, among others, Hapi Herb the sound sculptor, Bob the water feature consultant, two artists/sculptors, net fabricators, structural engineers, tunnel and slide manufacturers, civil engineers, play auditors, interpretive designers and equal-access auditors.
In Footscray, Big Fish (artist/sculptors/fabricators) is busily making banksia cubbyhouses with “lips” that look almost kissable, entry arbours, shade structures, sand tubes, bamboo chimes, bongo drums and thongophones. In Yackandandah, Agency of Sculpture is creating large acorn-shaped treehouses, interactive storm panels, rain and hail tubes, kaleidoscopes and portholes filled with insects. In Newcastle, net fabricator Kaebel Leisure is weaving a climbing net the size of its warehouse floor. I sometimes think the landscape contractor has the easiest part of the project.
The passion for a completely customized playspace that educates children on the importance of nature has kept me focused and challenged, and the opportunity to work with talented artists, and the dream of one day sitting in an acorn-shaped treehouse watching the sun set over the arboretum, has kept me motivated. It has been a wonderful and rare opportunity to be involved in this fascinating portion of an extraordinarily important and massive project.”