V Bienal Latino-Americana de Arquitetura Pasagística 2022

We bring here the “descriptive memory” of a naturalistic and seasonal garden planted at the Instituto Central de Ciências (ICC), an iconic brutalist building at the University of Brasília and a landmark of modern Brazilian architecture that was designed by Oscar Niemeyer and João Filgueiras Lima in 1962.

The Jardim de Sequeiro (Rainfed garden) extends through the 732 meters of the brutalist mega-structure, divided into modules interspersed with squares, passages and open spaces that allow natural ventilation and lighting for the building’s lower level. The garden’s elongated structure is visually delimited by a sequence of 243 prestressed concrete pillars on each side, and it’s flanked by corridors and classrooms. In total, there are more than 5,000 square meters of rooftop gardens planted on a thin layer of soil.

As an experimental garden grown mainly from seeds, the garden is dynamic. Beginning with the fast-growth species, plants bloom in succession throughout the summer and early autumn. The garden is “rainfed,” relying entirely on rainfall for water, and withers and dies with the arrival of the winter drought. As such, it can be considered a garden-installation: a temporary occupation that is redesigned and improved every year. 

The garden is in continuity with the savanna climate of our region. Its design reiterates the dynamic nature of the Brazilian savanna with the verdant beauty of the first flowers (late December) giving way to the chaotic magnificence of its later phases when the garden is full of butterflies and bees (March and April), and finally the autumnal beauty of decaying herbs (May). In June, the plants are dry but the garden is still the subject of aesthetic interest and capable of offering ecological services. Each cycle culminates with the harvest of the seeds for the next season. In July the remaining straw is ground up and left as a mulch to protect the soil. The area goes into rest until October, when the soil preparation begins, with sowing taking place in November.

Our hope is that the garden will help the public build connections with the native landscape and its seasons as they follow the plants from the bright greens of spring’s germinating seedlings into the earthy tones of winter such as the reddish tassels of native grasses, the darkest browns of zinnia (Zinnia elegans Jacq.) and rudbeckia (Rudbeckia hirta L.) seedheads and the almost white 1 meters long stems of mustard (Sinapis alba L.) flowers. We also hope that the large academic community that attends the Instituto Central de Ciências can follow the work of soil cultivation, garden care, seed harvesting and other activities, thus connecting with the techniques and rewards of gardening.

The concept of the garden was inspired by native open meadows and grasslands, and is part of the growing interest in the beauty of the savanna landscape of the Brazilian Central Plateau called “Cerrado”. The garden’s palette is primarily based on native grasses and annual flowers. Some exotic perennials, bulbs, edible and medicinal plants, including giant chincherinchee (Ornithogalum saundersiae Baker), aloe (Aloe Vera (L.) Burm) and linseed (Linum usitatissimum L.) has been added in order to enrich the garden’s composition and biodiversity. Several of these native species have never been used in gardens before.

During the rainy season, in addition to data collection and teaching activities, we have also held guided tours and photography, native bee management, watercolor painting, seed collection workshops. With these, our intention is to increase awareness of the joys that gardens and gardening can offer. During the winter months, video and photo expositions, speeches, workshops and artistic installations will keep the garden alive and the community’s imagination, even as the soil rests and the garden itself is reduced to its seeds, which are packed and preserved in cold chambers.

Conceived and planned during the initial months of the COVID-19 pandemic, the garden’s first cycle occurred between December 2020 and May 2021, when the university was closed. Despite the difficulties inherent to the pandemic period and the innovative nature of the project, the results were promising. Now in its third cycle (2022/2023), the garden is already in full “winter re-design mode”. The seeds – we now have enough to plant ten times our area and we are sharing seeds with other gardening initiatives inspired by ours – are stored, and our weekly activities are focused on educating the academic community, which has finally returned after over two years of remote learning, that while the gardens are gone now, a naturalistic parade is coming. We are also impressing on the community that the garden is seasonal; when the rainy season ends, the garden will fade away, following the seasons of our native Cerrado landscapes. 

For us as landscape designers, the biggest lesson has been confronting an enormous truth: that our field is, perhaps more than any other art form, a slave of time. There is a time for everything: a time to plant, to grow, to bloom, to dry, to wait, to work, to enjoy, to decay. This is a great challenge for landscape designers, understanding that this art not only takes time, but is also inherently transient.

Brief history and contextualization

Brazil’s decision to construct a new federal capital, Brasília, in the late 1950s was to foster the occupation of the country’s sparsely populated and savanna covered Planalto Central and to strengthen the country’s territorial unity. Brasília was designed by architect Lúcio Costa and inaugurated in 1960. The University of Brasília was created in 1962 by sociologist Darcy Ribeiro with the intent that the university would be the most important piece in the renewal of Brazil’s higher education. 

The Instituto Central de Ciências (ICC) is the main and most iconic building of the University of Brasília, and one of the landmarks of modern architecture in Brasília. In the 1970s, the long open space between the building's blocks was landscaped in the modernist style, as was the case with other buildings in the capital. A palette of plants composed of exotic species was installed, growing on a layer of earth that rests on the roof of scientific laboratories below.

For nearly fifty years, that garden was maintained with manual irrigation during the dry seasons (May and October), but with the local water crises of 2016 and 2017 in addition to the loss of funding for gardening services, almost all the vegetation cover in the area was lost. Even some ancient native palms (Syagrus oleracea (Mart.) Becc.), over 30 years old, couldn't resist; their roots, so strong and deep under natural conditions, were stuck in the concrete vase. Since then, the ICC, despite its central position for the daily life of the university, has not had its garden replanted. For us, it made no sense to replant a garden that would require financial and water resources that are no longer available.

In this context, a low-cost, seasonal garden was designed, implanted by seeds, using native grasses of the Cerrado and traditional short-cycle flowers in a naturalistic composition. The garden itself multiplies its seeds, which are used in the next cycle, and the garden’s yearly design and cultivation have become opportunities for teaching, research and university extension activities.

Planting Design

The garden’s design takes advantage of the contrast between its naturalist aesthetic and the brutalist architecture in which the garden is inserted and where concrete beams and pillars define its spaces. Moreover, the use of short stature herbaceous species allows for an unhindered view of the ICC’s central span. The choice of species is based on creating a dynamic and evolving palette, where species succeed each other in flowering from direct sowing, with earlier or later flowers interspersed with native grasses.

Within this compositional scheme, the species were selected to cohabit, weaving ecological relationships and presenting a dynamic of density that goes from a lighter and open formations at the beginning of the garden’s cycle to a denser and more diverse meadow in its final moments. The longevity of the garden comes from the succession of flowerings, unlike traditional and common monospecific flowerbeds found in the urban environment of Brasília.

As this is a garden that was designed to be redesigned every year, it is worth reporting here the plant designs of the first and second cycles, since there were relevant changes between the first two cycles of the garden. These changes reflect the search for better solutions, and are the results of experiments and the learning process.

The planting design of the first cycle was developed between May and November 2020, based on a study of references in the composition of naturalistic gardens, as well as observations from previous small experimental gardens and natural formations of the Cerrado, and prospection of species of interest (native and conventional). The second cycle’s planting design was carried out between July and October 2021 and this design was primarily based on what was observed in the garden during the first cycle and in other small experimental gardens distributed throughout the campuses of the university. For the second cycle, we were able to include new compositional techniques and new species.

It is worth mentioning that the planting designs of this garden can only be completed after the quantification of the seeds we obtained from the garden itself. Some native species are not easily found at local markets and, besides that, we only buy seeds that we cannot harvest directly from our garden. For the first cycle, the seeds were obtained from commercial suppliers and entities specialized in collecting and distributing native seeds aimed at environmental recovery; part of the seeds was collected directly in the field by the team. As of the second cycle, most of the seeds used were obtained in workshops for collecting and processing seeds from the garden itself.

2020-21 cycle: The planting design explores the growth dynamics of the species from three layers of composition: early flowers, late flowers and native Cerrado grasses.

Early flowers: Those flowering within 90 days were selected, with a light structure to allow the growth of grasses and late flowers among their foliage. In the composition, the early flowers compose open, extensive designs, with variable density and different associations. Its colors have blue as the prevailing tone, given by centaureas (Centaurea cyanus L.) and linseeds (Linum usitatissimum L.), sprinkled with warm tones of golden tickseed (Corepsis tinctoria Nutt.), dill (Anethum graveolens L.) and zinnias (Zinnia elegans Jacq.).

Late flowers: Species flowering after 90 days and with the ability to maintain flowering until the end of the rainy season. Late flowers, especially Salvias (Salvia farinacea Benth., Gaillardias (Gaillardia x grandiflora), were arranged in smaller and denser spots, with the function of supplanting early flowers when they lose interest, while Ornithogaluns (Ornithogalum saundersiae Baker) brings drama and verticality at a time when the garden would already resemble a meadow, with voluminous grasses. Besides these flowers, seedlings of the ornamental variety were also planted in monospecific patches of Euphorbia hypericifolia L. called euphorbia hip-hop.

Native Cerrado grasses: Species previously tested in experimental gardens were selected and they had, in addition to ornamental interest, the ability to bloom in the first growing season after sowing. In the grass layer, seven species of grass native to the Cerrado: fastigiato grass (Andropogon fastigiatus Sw.) carinato grass (Paspalum carinatum Humb. & Bonpl. ex Flüggé), orelha-de-coelho grass (Paspalum stellatum Humb. & Bonpl. ex Flüggé), membeca grass (Andropogon leuchostachyus Kunth), fiapo grass (Trachypogon spicatus (L. f.) Kuntze.), brinco-de-princesa grass (Loudetiopsis chrysothrix (Nees) Conert) and panasco grass (Aristida setifolia Kunth). These grasses were distributed in large patches of sinuous progress, forming the basis for the late flowers.

2021-22 cycle: For the composition of the garden in its second cycle, we started to use seed mixes and the extensive patterns of overlapping layers from the previous design were no longer used. We also started to work with the concept of forming a permanent backbone of native grasses, which is watered every 10 days during the drought and remains alive from one cycle to the next.

The seed mixes used were composed of 3 or 4 species of early, medium and late character, aiming to provide a succession of flowering throughout the season. For example: linseeds + golden tickseed + gaillardia. We added new species to the plant palette, like mexican zinnia (Zinnia haageana Regel), rudbeckia (Rudbeckia hirta L.), anise (Pimpinella anisum L.), and arugula (Eruca sativa Mill.), among others. The seed mixes were arranged in compositions by sinuous patches, from 5 to 20 m², covering the north and south wings of the ICC. These patches were interspersed with patches of native grasses and sprinkled with the occasional use of aloe (Aloe Vera (L.) Burm.) and gladiolus bulbs (Gladiolus sp hybrids) seedlings. At the “central wing”, a different design was created in order to accentuate the meadow nature of the garden: a mix containing 12 flowering species was designed to contrast with a mix containing mostly fastigiato grass and some zinnias and linseeds. 

The use of native grasses (except for fastigiato grass, which is annual) was changed to seedlings, due to the relative lack of success with direct sowing, which meant that they did not bloom during the rainy season. Because of this, it was decided that the existing clumps of native grasses would be watered (with a low frequency) during the drought so that they could participate in the next cycle. At the same time, seedlings of membeca, fiapo, prateado grass (Anthaenantia lanata (Kunth) Benth.) and others were produced in a greenhouse, and these served to enrich the base of native grasses in the garden.

General information 

In March 2020, the team of nine was assembled, and in April of that same year a study group on naturalist landscaping and Cerrado began to operate. Two small experimental gardens were carried out in July and August 2020, in order to collect data and for seed multiplication for the main garden sowing ahead.

The garden was sown in December 2020, with reseeding operations during the month of January and early February 2021, in order to correct the failures due to the low germination rate of some of the seeds, in addition to damage caused by leaf-cutting ants, pigeons, drought and others. The garden had its flowering peak between March and April, with seed collection taking place in April. The area was finally mowed between May and June 2021. 

With the end of the first cycle, in May 2021, a public selection was carried out to assemble the team responsible for the 2021-22 cycle of the garden. The resulting team totaled 26 participants, including members of the first-cycle’s team and new members. The team is diverse and includes landscaping professionals, university employees, members of the external community, and undergraduate students from various majors. 

The second garden cycle was sown in mid-November 2021 and began to bloom in early January 2022. The workshops and guided tours lasted from January to May 2022. From mid-April onwards, the drought situation led the garden to enter its dry cycle. Seed collection started at the end of April and lasted until May 2022, when the rest of the dry plants were shredded, and the winter treatments began. 

In addition to the direct activities of planning and cultivating the garden, activities in research, science communication and academic extension were carried out, with the aim of exploring the academic potential of the initiative and disseminating its results. Further information about each of these follows below. 

Research activities, technical development and practical results: the garden is innovative in our context in several aspects, including how it’s made by sowing, for its temporary nature, how it exists without irrigation and on a rooftop, for its use of native grasses and herbaceous plants, and for the naturalistic language of the composition. Our main goals are better understanding the cycle and the ecological needs of the species we use, enriching our plant palette, developing strategies for weed control and drought resilience, and design strategies for improving aesthetic achievements. There is a lot to learn and a lot of interesting information to collect. We have been prospecting native and exotic species adaptable to gardens like ours, carrying activities in laboratories and greenhouses (germination tests, seedlings experiments) and in small experimental gardens and the rainfed garden itself (developing sowing techniques and the use of shredded vegetable residue as mulching in sowing areas, aesthetic composition strategies, collecting phenological cycle data, and more). The main practical result of this research is the garden itself, but there are others: the re-use of the vegetal residue alone saves money that the university used to spend to carry it away: a monetary value that’s more than 10 times the estimate cost of the garden (US$5.000,00 per cycle).

Science communication: 21 open lectures/open classes about the initiative during were held during these first cycles. The project was also the subject of newspapers articles (2) and TV broadcasts (3, one of which was on a national network). One article was published in scientific publication. The garden also has a large social media presence, with both team members and members of the community sharing photos and videos online. 

Academic Extension: so far 46 extension events were offered, including guided tours, numerous workshops (photography, watercolor, floral arrangement, edible flowers, identification and management of native bees, and seed collection and processing). These workshops were open to both the academia and external community, and more than 1,500 applications for participation were received for the events.

This garden is an initiative that unites academic activities and the administrative management of landscaping services of the University of Brasília. Its project has been embraced by the university’s administration and, by its third cycle, 40 people, including volunteers, students and university employees are now responsible for the field work.