White’s thoughts on vegetation-bearing architecture crystallize in his patent of 1938, yet notions of a green wall emerge as early as 1931 in his lectures and writings on the modern garden. Although the intended audiences for White’s early writings on vertical greenery are not yet apparent, the idea of a vegetation bearing garden enclosure preoccupies him for several years as documented in his personal journals, or Commonplace Books, in the University of Illinois Library Archives. Technical aspects of White’s green wall find their clearest articulation in US Patent 2,113,523, filed on 18th August 1937, yet the theoretical dimensions developed as a treatise on modernism and garden design, in which the vertical surfaces of the garden create a backdrop for modern living. In an essay titled ‘What is Modern’, White discusses the green wall as a design solution for the modern garden, allowing for the preservation of a free plan and composition of a garden in the vertical dimension. His references to Walter Gropius, Le Corbusier, Frank Lloyd Wright, Louis Sullivan, Walt Whitman, Charlie Chaplin, Norman Bel Geddes, Adolph Appia, Sheldon Cheney, Walt Disney, and others, situates the work among a group of ‘moderns’ concerned with changing lives through art and architecture.The Vegetation-Bearing Architectonic Structure and System evolved as a response to the problem of modernism in garden design, and is a unique contribution of landscape architecture to this effort, representing a clear translation of garden theory into garden form and legalese. The prescience of this work is astounding,mobile grow rack predicting not only the emergence of the vertical garden in the contemporary built environment, but a method of scholarship in patent development not widely accepted by US universities until the 1970s.

The first drawings of a green wall appear in White’s Commonplace Books in 1932 as two humble sketches of a wall section and elevation. White’s elevation sketch shows a wall composed of vertical greenery, decorative insets, lights, fishes, and birds occupying the inset voids. His section sketch reveals a soil filled wall structured with interior irrigation and voids for compositional elements. Annotations in the Commonplace Books Index identify the sketch as an idea for the Century of Progress Exhibition in Chicago, and as his first sketches of Botanical Bricks.Although technical records of these original experiments remain elusive, the spirit of discovery permeates White’s Commonplace Books. His dreams of patents, economic freedom, worlds fairs, and recognition for his invention were only partially realized until dissolution of his most fanciful dreams into preoccupations with wartime efforts. White’s journal entries of the period document a radical shift in 1938–40 from his interest in development, marketing, and distribution of botanical bricks, to an emphasis on newspaper clippings and current events. White was not alone, as World War II captured the collective conscience of architecture, design, and society towards new ends and modes of production.White’s inchoate drawings and description of a green wall in 1931–32 mature until his application for the Vegetation-Bearing Architectonic Structure and System on 18th August 1937, where he artfully translates garden theory into United States Patent and Trademark Office legalese with the help of his attorney, Elmer Hovenden Gates of Arlington, Virginia.The new art of vegetation bearing architecture was entirely novel at the time of application, and no citations of prior art are associated with White’s invention. Currently, thirty four international patents cite US Patent 2,113,523 as prior art, encoding an array of inventions from grass cube chairs, to vegetation-bearing gabion walls.Interestingly, White’s lawyer, Elmer Hovenden Gates, and proposed business partner, William M. McPherson, patented related vegetation-bearing technologies within weeks of his submission.

More than 50 patents cite the Vegetation Bearing Cellular Structure and System, Vegetation-Bearing Display Surface, and the Vegetation-Bearing Architectonic Structure and System, collectively encoding a diverse ensemble of environmental technologies. The legalese defining this new field offers valuable insights into the founding principles of vegetation-bearing architecture as a chimera of architectonic structure and vegetated system. According to White, architectonics relates to ‘the art of landscaping structure as well as to buildings, but distinguished from the art of plant culture’.Within this architectonic structure, plant growth is supported through a layering of horticultural substrates and reticular materials. In this configuration, the ‘vegetation in its final positions has its roots within the compost while the tops of the vegetation would extend through the reticular surfaces of the units or compounds into the open air where their normal development occurs’.The patents legalese describes not only the technical specifications of White’s new invention, but also the proposed scope of vegetation-bearing architecture as a new art. This scope is of particular interest with the emergence of the vertical garden and green wall in the contemporary built environment, as the language that defines the new art also encodes innovations in related technologies today.White’s vision of rapidly assembled and scalable plant-bearing architectonic structures adopts principles from modular building and construction techniques, situating his invention among the array of building products developed during the early decades of the twentieth century. The common name Botanical Bricks further reveals White’s notion that his modular building units be integrated into the building arts as commonly as bricks in gardens and architecture. Potential application listed in the patent range from camouflage, concealment, decoration, backgrounds, and screens for use in architectural project . Contrasts between White’s proposed applications, and contemporary notion of vegetated architecture as a sustainable technology is especially salient, as language to describe sustainability or environmental performance had not yet been established. The field of vegetation-bearing architecture was rapidly expanded by two contingent patents filed on 4th April and 28th May 1938 by William M.

MacPherson and Elmer Hovendon Gates, respectively. These patents reinterpret the structural system proposed by White in which the vegetation bearing units assemble like masonry or bricks, and are essentially self-supporting through stacking and repetition . Consecutive to this, patents by Gates and MacPherson envision vegetation-bearing units supported within a structural and load-bearing framework, and vegetation bearing units secured to a self-supporting wall as a veneer or surface system. Although the structural iterations presented by each patent alter the load bearing relationship of the vegetation to the structural element, the new art, as described by White, remains remarkably resilient to these adaptations and contemporary permutations.Patent application for the Vegetation-Bearing Cellular Structure and System was filed by William M. MacPherson on 4th April 1938, and was granted on 21 June 1938, under the legal guidance of Elmer Hovenden Gates.MacPherson was a graduate of the University of Illinois in architecture and taught at the Lake Forest Academy from 1932 to 1933, where White was the director. After departing Illinois, MacPherson attended Columbia University where he received an Master of Science in architecture and worked at the USA Housing Authority from 1937 to 1940.Although the exact relationship to White remains unclear, MacPherson is mentioned in White’s journals as a potential business partner and collaborator for patent development along with Elmer Hovenden Gates. Irrespective of this dynamic, MacPherson was able to patent a vegetation-bearing technology that adapts the structural system of White’s Botanical Bricks to a load bearing matrix into which the planted units may be inserted .Although the structural modifications proposed by Gates and MacPherson reorient the relation of the vegetation-bearing unit to the underlying structural system, the basic technology and principles remains intact. The resilience of White’s new art is found in its aptitude for reinterpretation, as he defines a relationship between plants and structure that elucidates their interdependence and interstices. Triangulations between the building sciences, horticultural arts, and landscape theory are seminal to White’s conception of the Vegetation Bearing Architectonic Structure and System. White received a Bachelor of Science in agriculture from Cornell in 1912, his Master of Landscape Architecture from Harvard in 1915.His background in science and design undoubtedly contributed to a synthetic approach to plants, structure, and garden form, yet it is a convergence of material innovations and new scientific discoveries that make the vertical garden possible, and timely, in the 1930s. Innovation in building materials occurred rapidly in early years of the twentieth century, as industrialization and wartime research fueled experiments in architecture and the sciences alike. Material Sciences flourished during World War I and material product lines expanded through the roaring twenties,ebb and flow table radically impacting architecture and the production of buildings.

New building materials were readily tested, and exhaustive volumes of literature were published to disseminate information in an ever-changing marketplace for architects and designers. Building material bibliographies from the era document rapid integration and research on materials such as armorphy, clay tile, plywood, glass block, masonite, rostone, vinylite, celotex, porcelain, zonolite, to name just a few.Concurrent to the expansion of new materials in architecture, was an expansion of the role of popular science and a belief that technology would improve modern living. In agriculture, new technologies such as hydroponics, popularized in the 1930s, promised to create new productive systems that would increase yields and feed a growing population with increased efficiency. White’s invention exists at the intersection of these spheres of innovation, where the differentiation between horticultural system and building system begins to blur. Efforts towards new and efficient forms of building assembly paralleled new and efficient forms of agriculture.White also suggests that the substrate may be entirely inert through the use of building insulation as a growth substrate, proposing that the ‘soil substitute or compost for vegetation growth may be made with any of the mineral fibers used for insulating purposes or any other suitable substance of low specific gravity to take the place of the relatively inert mineral soil particles of natural earth’.The integration of inert substrates into Botanical Bricks establishes a direct correlation between vegetation-bearing architecture and the science of hydroponics, or soilless culture. Interestingly, it appears that White actually predicted the use of mineral wool in hydroponics, as the material was not fully integrated as a growth medium until the late 1960s when Grodan Rockwool first became commercially available.Experimentation with growth substrates has continued in the field of hydroponics to include inorganic materials such as vermiculite, mineral wool, expanded clay, polyurethane, polystyrene, polyester fleece, and zeolite, continuing to expand the role of building materials in plant growth systems.White’s knowledge of hydroponics, or aquiculture as it was previously known, is clearly articulated in the patent of 1938 through discussions of chemical requirements for plant growth in artificial substrates. Divisions between substrate and nutriment allowed White to speculate about the use of inert and lightweight substrates in his Botanical Bricks, but these unnaturaldivisions between native soil and inert substrate should be credited to pioneering work of William F. Gericke, founder of modern hydroponics, who laid the conceptual foundation for White to build upon.The layering of wire mesh, burlap, and asphalt paper encapsulates the hydroponics substrate and supports plant growth, creating a system detached from native soil through the use of layered building materials.He proposes that the horticultural substrate be retained by material include wire fabric sheets, expanded metal, and meshed chain mail fabric, perforated plastic sheets, reinforced by structural members to accommodate load-bearing capacity. Gericke’s experiments were a liberating force, allowing for further separation between plants and soils, and the advancement of new possible relations between plants and structure. Although the substrate used for Gericke’s original experiment was limited to sand, further trials included gravel, sand, cinders and new construction materials such as Gravelite , which found use as a lightweight aggregate in construction in and hydroponics experiments simultaneously.By the time Gericke’s research reached the general public in 1940, Stanley White’s patent was already granted, yet both innovators predicted the evolution of plant growth away from native soil, towards a fecund interdependence with technology, structure, and new materials.Although copper-based engineered nanomaterials currently comprise a relatively small fraction of global ENM production ,1 their toxicity and life cycle characteristics raise concerns regarding their environmental risk. For example, a common use for Cu-based ENMs is as the active ingredient in marine antifouling paints or agricultural biocides,2 where they are directly introduced into the environment as intentionally toxic substances. Copperbased ENMs are somewhat unique among the most widely used ENMs in that they can participate in redox reactions to form three oxidation states: Cu0 , Cu1+, and Cu2+.