As a short theoretical basis for our work at the chair, we invoke 10 theses, which I formulated for the exhibition in the Architekturgalerie Luzern in 1992 and which, in a slightly revised version, we consider continue to remain valid.

1.
Our work is a search for the Nature of the City, whose color is not solely green but also gray. The Nature of the City rests in its elements: the tree, hedge, lawn; but equally the water-permeable hard surface, broad square, rigid street-gutter line, high wall; and the unobstructed fresh-air or visual axis, the center and the periphery.

2.
Our interests focus on the city and its inhabitants. The city is no longer a monolithic entity; instead it is dismembered and fragmented into thousands of parts. City dwellers are a kaleidoscope-like mixture of young and old, immigrant workers and long-established locals, clergy and junkies, managers and eco-freaks. This heterogeneity demands up-to-date actions and reactions in outdoor spaces that reject a uniform greening of the city.

3.
The traditional city–countryside rivalry has disintegrated, the boundaries have blurred. We assume that it is impossible either to dismantle the city or to rejuvenate the countryside. Nevertheless, the legibility, the perceptibility of the world is rooted in the principle of dissimilarity. Considering this synchrony of city and countryside, the coming task is to stop the further erosion of the inner boundaries and splits. They have to become sensuously perceptible again.

4.
The city, with its outdoor spaces, cannot be planned as a whole. We trust in mosaic-like interventions in the hope that they will result in meaning and the ability to be experienced, not just of the particular place but also of the whole.

5.
We pay particular attention to the innumerable non-places produced by bureaucratic planning and design. We consider that urban-planning interventions, which equally include landscape architecture, are all the more crucial on the periphery—in those unloved leftover metropolitan spaces.

6.
We understand garden architecture as an expression of the spirit of the times. It is anchored in current social, cultural, and ecological events, which in turn can only be understood in their historical context. For us this means critically confronting the core themes in garden art, or better garden culture, which include not only the achievements of the Age of Feudalism but equally the modest gardens of the simple folk. For us, working with our co-disciplines of architecture, engineering, and the visual arts is not an unwelcome obligation but a welcome axiom. Working together generates mutual innovations. Grappling with the events of the here-and-now requires the inclusion of the wider cultural environment, engaging with film and video, philosophy and literature, music and advertising. We listen to Bach and Schönberg, but similarly Laurie Anderson and Phil Glass. We immerse ourselves in Sol LeWitt and Walter De Maria, Christo and Carl Andre. We find receptions of the themes of nature and the garden not only in Goethe’s Elective Affinities or Stifter’s Indian Summer but also in Bloch’s Alienations, Handke’s The Lesson of Mont Sainte-Victoire, or Sennett’s The Conscience of the Eye. In Mon Oncle, Jacques Tati leads us from his lovingly tended roof garden through urban wastelands to the bizarrely designed garden of his brother-in-law, while in The Draughtsman’s Contract, Peter Greenaway imparts a lesson in the art of the garden and its social determination.

7.
A further basis of our landscape architecture is the reference to place. This all-too-often adulterated idea is crucial to our work because it prevents solutions from becoming arbitrary and interchangeable, giving more scope to the particular than the generic. Starting from a reading and analysis of the place—its cultural, ecological, and social state—we develop a concept that tests the viability of what exists, either keeping it completely intact, reshaping it, newly interpreting it, or indeed neglecting it. The decisive aspect in this process remains the authenticity of place, as defined by form, material, and use. This is the opposite of a timid conservational approach, which aspires more to recreate the past and which does little to help the future to again become the past. Gardens, parks, and squares should be allowed to tell their history, but they should also be able to tell new stories. They are poetic places of our past, present, and future.

8.
With the transformation of Baroque gardens into English landscape gardens in the eighteenth century, a garden form emerged in which both of their contradictory essential features are combined. Scornfully derided as an inferior potpourri of styles, recently people have now come to recognize the quality and modernity of these gardens. In their analysis of Cubist painting and architecture, Rowe & Slutzky define transparency as over-layering, multidimensionality, and mutual permeation of various structures and systems, allowing a simultaneous and ambivalent reading. To us, the principle of transparency seems ideally suited to the creation of urban outdoor spaces. It affirms the variety, the heterogeneity of the city and its inhabitants, can absorb the old and the new, evokes a pictorial quality—dialectical places in which society, but also individuals, can re-find themselves.

9.
Nature has become scarce in the city and the countryside. The natural bucolic has now become the highest quality label. Like the cultural amenities of the past, a city’s nature amenities now define its location advantages. We think, considering this unprecedented social consensus, that formulating concepts for the Nature of the City is imperative. The essential thing is to rediscover the plant as an urban element, and not to consider it simply as an ecological or dendrological factor, as an architectural filling element. We should learn that there are different shades of green, that plants rustle differently in the wind, that not just flowers but also fallen leaves have a fragrance. We should include shade, take account of the impression of the bare branches in winter, express the symbolism of plants, and feel their sensuousness.

10.
It is fashionable for people to prove their progressive credentials by promoting naturally grown, native vegetation. The regulations and rules read that planting exotic trees and shrubs is forbidden. Waving the warning about imminent ecological collapse, plane trees, butterfly bush, and sweet mock orange have been declared “enemies of the garden,” and instead nettles, plantains, and mugwort have become protected species. Quite rightly, the environmental movement has criticized the absurdity of the weekly ritual of spraying herbicides and the planting of ground-covering monocultures. Nonetheless, this strict rejection of cultivation, selection, and grafting is equally irresponsible because it negates centuries of manual craft and thus garden culture in itself. No one would seriously argue that the crab apple is superior to the Bern rose apple—and every now and then we all secretly love to eat potatoes! “Give the Foreigners a Chance” was Jürgen Dahl’s plea in an article in Die Zeit, by which he meant plants, animals, and people alike. We wholeheartedly support this call. City vegetation thrives with and from its polarity: it is trimmed and grows wild, is multicolored and uniformly green, lush and bare, native and foreign. Plants are useful. They improve the climate and are a habitat for animals and people. But plants also stand for the city’s promise of nature, which has a special significance for our everyday lives. Bertolt Brecht expressed it as follows: “Asked about his relationship to nature, Mr. K said: ‘Now and then I would like to see a couple of trees when I step out of the house.
Particularly because, thanks to their different appearance, according to the time of day and the season, they attain such a special degree of reality. Also, in the cities, in the course of time, we become confused because we always see only commodities, houses and railways, which would be empty and pointless if they were uninhabited and unused. In our particular social order, after all, human beings, too, are counted among such commodities, and so, at least to me, since I am not a joiner, there is something reassuringly self-sufficient about trees, something that is indifferent to me, and I hope that, even to the joiner, there is something about them that cannot be exploited.’ ‘Why, if you want to see trees, do you not sometimes simply take a trip into the country?’ he was asked. Mr. Keuner replied in astonishment: ‘I said, I would like to see them when I step out of the house.’”*

* Bertold Brecht, “Mr. K and Nature,” in Stories of Mr. Keuner, trans. Martin Chalmers (San Francisco: City Lights, 2001), 17.

In Anette Freytag, The Landscapes of Dieter Kienast (Zurich: gta Verlag, 2020), 403–5. Thomas Skelton-Robinson translated the ten theses for this volume from the last amended version from November 1998 by Professor Dieter Kienast, Chair of Landscape Architecture at ETH Zurich, as published in Dieter Kienast: Die Poetik des Gartens; Über Ordnuung und Chaos in der Landschaftsarchitektur, ed. Professur für Landschaftsarchitektur ETH Zürich (Basel: Birkhäuser, 2002), 207–10.