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Educating for sustainable horticulture

Volume 7 Number 2 - October 2010

Keith Tomlinson

French: Vers un curriculum horticole durable

Spanish: Educando un currículo sustentable en horticultura

The creation of a Sustainable Horticulture course by Meadowlark Botanical Gardens and the Northern Virginia Community College is bringing elements of botanical and ecological training into a programme of traditional horticulture.  In this new forum, which contributes to Target 15 of the GSPC, Keith Tomlinson argues that students can consider the ecological implications of their work and ensure that native plants receive more attention in horticultural design and application – particularly in urban settings.

This new course was set up in the spring of 2009, as part of the Horticulture Technology Program at the Northern Virginia Community College (NVCC).  This popular two-year course of instruction has produced many trained horticulturists in the Washington DC metropolitan area since 1974. Students carry out coursework in horticultural botany, soils, propagation, landscape design, landscape construction, GIS applications and herbaceous and wood plant identification. Many of the plant identification laboratories use collections at Meadowlark Botanical Gardens (MBG). Several full-time and part-time staff at Meadowbank are NVCC alumni and in 2007 initial discussions between MBG staff and NVCC Horticulture Program began considering a Sustainable Horticulture course that would focus on increasing regional native plant diversity in landscape applications.

Graduates of the NVCC programme work in a diverse array of horticultural settings. Many are independent landscape contractors or work for large commercial nurseries. Some specialize in mass propagation and marketing seasonal crops (poinsettias, chrysanthemums, pansies, fruit trees) and some work in public gardens. Others go on to four-year specialized programmes. With this range of vocational targets, it is clear that providing sustainable horticulture training to this particular student body could have far-reaching impact for conservation in the landscape and nursery setting. There are over 140 community college horticulture programmes in the United States alone.

Former Director of the United States Botanical Garden and NVCC Horticulture Program Head, David Scheid, initiated the idea of a Sustainable Horticulture Course with the Curriculum Advisory Committee and the NVCC Dean of Applied Sciences. MBG staff were recruited to design and teach the course in 2008, and in spring 2009 a 16-week, three-credit course was offered. Enrollment rapidly reached the maximum of 25 students, demonstrating a keen interest in the topic.

Fostering ecological sustainability in the Horticulture Curriculum 

Horticultural landscapes in the Mid-Atlantic region of the USA are rich in non-native ornamental species, often creating an aesthetically pleasing scene. They are, however, frequently ecologically barren and even degrading to the environment. Very few ornamental plants are patronized by native insects, creating a biomass deficit at a low trophic level (Tallamy, 2007). In addition, many popular ornamental plants are not ‘ecologically stable’ and rapidly become invasive. In the metropolitan Washington DC area, Bradford pear (Pyrus calleryana), Miscanthus grass (Miscanthus sinensis) and English ivy (Hedera helix) are just three examples. All are widely available in the regional nursery trade and frequently sought by local homeowners and businesses. Thus, the troublesome use of such species must be addressed by this new curriculum without compromising its strong aesthetic element.

Tackling these issues in the classroom setting requires an increased use of botanical, biogeographic and particularly ecological subject matter. This approach is not intended to question the traditional strengths of horticulture programmes, which have historically been so successful in combining aesthetics and science. Surely, all botanical gardens benefit hugely from such training and in many cases offer it in the form of core educational programmes.  However, we are arguably reaching a crucial moment in the quest for global sustainability, when horticultural practitioners can apply their extensive knowledge to the collective effort of conserving plant diversity – locally, regionally and internationally. This process will require a modest curricular reorientation that results in a potentially huge benefit, brought about by decreasing the use of non-native plants and increasing the use of native species, thereby contributing to T15 of the GSPC.

Floristics and ecoregions

Floristics is the science of what grows where and why and has long been a foundation of plant ecology, but rarely applied to horticultural practice. The Sustainable Horticulture course at NVCC begins with a discussion of floristics as an introduction to the diversity of native plants. This discussion can take place in any horticulture curriculum anywhere in the world by using Armen Takhtajan’s seminal work, Floristic Regions of the World (Takhtajan, 1986). An instructor in Accra (Ghana), Hamburg (Germany) or Guilin (China) can use this single text to great effect. Other efficient means of illustrating the need for sustainability in horticultural design is to use both the International Agenda for Botanic Gardens in Conservation and the Global Strategy for Plant Conservation as curricular tools. Both documents contain objectives potentially useful to the student of sustainable horticulture. In such ways, the relevance of conservation programmes in botanic gardens can be instilled into horticultural education.

Complementing the floristic approach, there is now the means to become familiar with ecoregions. Recent work by the World Wildlife Fund and Conservation International has resulted in detailed ecoregional maps of the entire globe (Olson et al., 2001). Closely allied to floristic concepts, ecoregions provide a critical spatial and biogeographic foundation for horticulture students training in landscape design and maintenance. Thus, a core objective of the NVCC Sustainable Horticulture course is to foster a design process incorporating both ecologic and floristic factors to site analysis. Ideally, this process can lead to outstanding landscapes of innovative design, ecological stability and biogeographic relevance. Such landscapes will, of necessity, use primarily native plants.

Choosing regionalism over human abstraction and the exotic

A philosophical aspect of the NVCC Sustainable Horticulture course is internalizing the unique qualities of one’s own ecoregion and its biogeographic composition. Initially this can be a challenge, as we are consistently schooled to understand the state or country where we live in predominantly cultural terms. However, in nearly all cases political boundaries bear little or no relation to the natural distribution of biota (Tomlinson, 2001). Further, as students of natural history and plant science we rightly marvel at the tales of exotic plants from far afield. This work has encouraged the pursuit of exotic species in our gardens and landscapes (and still does). We are enriched and indeed profoundly educated by these horticultural wonders. Yet, in 2010 we are not driven so much by exploration as by the pressing need for conservation and sustainability (Friedman, 2008). Today, we can only explore plant habitats that we also conserve and effectively sustain.

Emphasizing regionalism, floristics and biogeography can realize a new synergy between horticultural applications and sustainable landscapes.  Moreover, this process can promote the conservation of plant diversity beyond botanic gardens and wilderness areas. Thus, this horticulture course is designed expressly to encourage students to consider the opportunities and implications of their work as a practical method of conserving plant diversity. Clearly, this is a philosophical departure from most horticulture curricula in its emphasis on ecologic integrity over exotic display. As botanic garden educators we must strive to reach the widest possible audience. Our success will be measured not just within the collections we interpret, but in the landscape beyond our gardens – a landscape much in need of sustainable management through ecologically focused horticulture.



  • Friedman, T., 2008, Hot, Flat and Crowded. Farrar, Straus and Giroux, New York, USA.
  • Olson, D., et al., 2001, Terrestrial Ecoregions of the World: A New Map of Life on Earth. BioScience, 51:11.
  • Takhtajan, A., 1986, Floristic Regions of the World. University of California Press.
  • Tallamy, D., 2007, revised 2009. Bringing Nature Home. Timber Press, USA.
  • Tomlinson, K.P., 2001, A New Conservation Initiative at Meadowlark Botanical Gardens, USA: The Potomac Valley Collection. Botanic Gardens Conservation News.
  • Wyse Jackson, P.S. & Sutherland, L. A., 2000, International Agenda for Botanic Gardens in Conservation, Botanic Gardens Conservation International, UK.
  • Secretariat of the Convention on Biological Diversity, 2002, Global Strategy for Plant Conservation, Quebec, Canada



Au printemps 2009,  les Jardins Botaniques Meadowlark et le programme technologique horticole de Northern Virginia Community College ont créé un cours Horticole Durable. Ce cours a pour but d’apporter des éléments écologiques et botaniques au programme de formation horticole traditionnel. Par conséquent, les élèves étudiant des matières telles que le design, l’agencement paysagiste, la propagation et l’usage des  plantes ornementales, ont l’occasion de prendre en compte les implications écologiques de leur travail et de leur formation. L’objectif éducatif est de fournir un forum où les végétaux natifs reçoivent plus d’attention dans les designs et les applications horticoles dans les zones urbaines. Grâce à ce procédé, un paysage écologiquement durable est envisagé pour la promotion de l’excellence esthétique ainsi que des richesses biologiques. Collectivement, ces objectifs assureront une compréhension plus grande de la conservation de la diversité végétale parmi les horticulteurs formés au niveau  du Associate Degree.


En la primavera del 2009 Los Jardines Botánicos de Meadowlark y el programa tecnológico de Horticultura en el Colegio de la comunidad de Virginia crearon un curso de Horticultura sustentable. Este intenta reunir los elementos de los curricula  de botánica y del programa de entrenamiento tradicional de en horticultura. En el los estudiantes cursan temas como diseño, instalaciones de paisajismo, propagación y en un sentido amplio, el uso ornamental de las plantas, teniendo así la oportunidad de incluir implicaciones ecológicas en su trabajo y entrenamiento. El objetivo educacional es proveer un foro donde las plantas nativas/indígenas reciben una atención especial en el diseño y su aplicación, particularmente los referentes a la instalación o planificación de árboles urbanos. A través de este proceso, el paisajismo ecológico sustentable habilita el promover la excelencia de la estética y la riqueza biológica. En conjunto, estos objetivos aseguraran un entendimiento mas profundo de la conservación diversidad nativa vegetal entre los horticultores y los grados de educación asociados.



Keith P. Tomlinson
Meadowlark Botanical Gardens
Vienna, Virginia USA


Amanda R. Tomlinson
The Renaissance School
Charlottesville, Virginia USA