This article is reprinted with the authors’ permission from the Spring 2011 issue of the Wellesley College Friends of Horticulture (WCFH) Newsletter. Photos courtesy of WCFH.
by Dave Jacke and Keith Zaltzberg
How well can we design a plant community that mimics the properties, principles, patterns and processes of natural ecosystems but produces food and other products useful for humans? The desire to explore this question lies at the heart of Wellesley College Botanic Gardens’ (WCBG) newest project: the Edible Ecosystem Demonstration Garden. The first of its kind at a college botanic garden, the Edibles Garden represents a major new thrust in ecological research: experiments in regenerative, whole ecosystem design. This landscape, designed with the assistance of a number of students and the support of many academic departments, mimics the forest in structure and function while providing diverse yields of food, habitat, and research opportunities.
Mimicking the mutually-supportive relationships found in healthy forest ecosystems, this garden will build and cycle nutrients efficiently allowing for high yields from a low-input system. Students and researchers will evaluate these dynamics over time, reshaping the edible ecosystem as our understanding deepens. The overarching goal of the new garden – to provide ample opportunities to learn about food-producing ecosystems in an aesthetically appealing setting – furthers WCBG’s focus on food of all kinds.
Conditions Determine Habitat
The Edibles Garden is designed to inhabit a portion of the meadow slope west of Observatory Hill. The site’s variable conditions support the development of several distinct edible habitat types: old fields, shrub thickets, open woodland, denser woodland edge, and mature tree understory, all within ¾ of an acre. The landscape’s topography suggests the feeling of a bowl, and the garden design enhances this feeling by planting trees and shrubs whose mature sizes descend to the ground in height as one moves east from the western tree line. The design concept of a “bowl of fruit” comprises the core of the garden: semi-dwarf fruit species that will be able to reach up for the sun without blocking views, astronomical observations, or shading the garden any further.
Low vegetation will be planted in the upper reaches of the west slope. At the top of the hill, major sight-lines from the telescope pads outside the newly-renovated Whitin Observatory toward Galen Tower, into the valley toward Paramecium Pond, and into the northern stream valley will be maintained. The meadow oak, the predominant tree specimen to the southwest, will be pruned to improve the use of the telescope stands for astronomy students in a key sector of the night sky, and to increase the area receiving at least six hours of sunlight during the growing season. The garden design includes the development of the area under the oak’s canopy into an outdoor classroom.
Designing for Habitat Diversity
The mosaic of habitats in the Edibles Garden will provide a diversity of foods for creatures of all kinds. Among the specific habitats planned are:
Nut Grove, a mid-height tree canopy adjoining the tall forest to the west of the garden. The canopy is intended to be dense, allowing little light to trickle through when mature. Its understory will consist of large patches of groundcover.
Fruit Woodland, a few well-spaced, drought tolerant, semi-dwarf fruit trees with a few fruiting shrubs thrown in for good measure. A few patches of densely planted perennial vegetables present themselves here. The understory will consist of diverse, edible, soil-improving, beneficial-animal attracting, and ground covering plants.
Eddow (edible meadow), which will grow in two areas where low vegetation is needed for aesthetic and practical purposes, and where soils are too dry for trees to thrive. It consists only of herbaceous vegetation, including perennial grain species. There will be some areas surrounded by plastic rhizome barriers, which will prevent the vigorous rhizomatous root crops planted within them from taking over the meadow. This habitat will be mown at least once per year to set back succession and to keep woody species to a minimum.
Fruit Thicket, which provides an edge environment and wildlife corridor between the habitats. The overstory consists of densely planted patches of low- to medium-height shrubs; the understory is intended to be a variety of groundcover polycultures.
The fine art of species selection for ecosystem design can wrack the brains of the best of us. One must weigh large sets of variables about any given habitat while attempting to match many different plants to these variables. Wellesley College students worked with us to research edible plant species that require minimal care while still yielding well and supporting plant species that enhance soil fertility and help minimize pest and disease outbreaks. The results of their research were presented at the College’s Ruhlman Conference this past spring.
Major paths and areas of the Edibles Garden were staked out on Observatory Hill in 2010. In the spring, we commenced sheet mulching to control crown vetch and other weeds, and planted our first round of woody species. Friends of Horticulture volunteer docents can look forward to adding the Edibles Garden to outdoor tours, as it will tell a compelling story to visitors, be comfortably designed to accommodate tour groups, and is situated only a short walk from the Visitor Center. Be sure to check out WCBG’s new garden whenever you get to campus – its growth toward maturity and natural succession will make it an ever-evolving, delicious place to enjoy.
Following is a partial list of plant species under consideration for the Edible Ecosystem.
Dwarf Korean chestnut Castanea crenata
Chinquapin Castanea pumila
Plum yew Cephalotaxus harringtonia, male & female
European filbert Corylus avellana cultivars
Pawpaw Asimina triloba ‘Taytwo’
American persimmon Diospyros virginiana ‘Ruby’
Goumi Eleagnus multiflora
Semi-dwarf Asian pear, 3-on-1 combo, Pyrus bretschneideri ‘Chojuro-Kosui-Kikisui’
Semi-dwarf European pear, 3-on-1 combo, Pyrus communis ‘Seckel-Bosc-Comice’
Contorted jujube Ziziphus jujube ‘So’
Perennial sweet leek Allium ampeloprasum
Groundnut Apios americana
Woodland strawberry Fragraria vesca ‘Intensity’
Indian ricegrass Achnatherum hymenoides
Asparagus Asparagus officinalis
Fennel Foeniculum vulgare
Giant sunflower Helianthus giganteus
Jerusalem artichoke Helianthus tuberosus
Wild bergamot Monarda fistulosa
Black chokeberry Aronia melanocarpa
Oregon grape Mahonia aquifolium
Japanese bush cherry Prunus japonica ‘Nakai’
Arctic raspberry Rubus arcticus ssp. stellarcticus
About the Authors
Dave Jacke, Dynamics Ecological Design, has been a student of ecology and design since the 1970s, and has run his own ecological design firm since 1984. He holds a B.A. in Environmental Studies from Simon’s Rock College and a M.A. in Landscape Design from the Conway School of Landscape Design. He is the author of the two-volume book, Edible Forest Gardens, the definitive reference text in this new area of horticulture. Dave’s grandmother,’09, mother,’47, and sister, ’74, are all Wellesley graduates.
Keith Zaltzberg, Regenerative Design Group, is an ecological designer who draws on his experiences as an instructor and organic farmer to create beautiful, vital and productive landscapes. Keith holds a B.S. in Environmental Design from the Department of Landscape Architecture and Regional Planning at the University of Massachusetts – Amherst.
Note: The full design report and implementation plan are available for sale at www.edibleforestgardens.com.