Sustainable Landscapes

1992 Annual Report for ANE92-009

Project Type: Research and Education
Funds awarded in 1992: $0.00
Projected End Date: 12/31/1995
Matching Non-Federal Funds: $83,482.00
ACE Funds: $75,000.00
Region: Northeast
State: Rhode Island
Project Leader:
Richard A. Casagrande
University of Rhode Island

Sustainable Landscapes


Through a collaborative effort involving faculty of the University of Rhode Island (URI) and the University of Massachusetts, we have developed and distributed a list of sustainable landscape plants for the region. The present edition of this list includes trees and shrubs that are adapted for various environmental conditions and landscape uses within this region. Over 5,000 copies have been distributed to nursery producers, landscapers, landscape architects, tree wardens, town planners, transportation departments and others involved in selection and establishment of trees and shrubs throughout the Southern New England states. The purpose of this list is to promote the production and use of low maintenance landscape plants.

We completed a manual for designing sustainable landscapes which emphasizes plant growth requirements and attempts to minimize the plant stresses that often cause pest problems. This manual is in the form of several introductory chapters and tables added to the second edition of the Sustainable Plant List, published in February, 1995. The list/manual contains descriptions of the plants including information on size, shape, shade and salt tolerance, soil and moisture requirements, etc. Written for professional landscapers but in language applicable to homeowners, it has been distributed, like the earlier editions, to landscapers, nurserymen and homeowners through Cooperative Education channels and through cooperating garden centers. It is also available on the World Wide Web through the Massachusetts Horticultural Society.

Many of these plants have been planted on the URI campus to allow easy evaluation and promotion of them. They are featured in URI's new Learning Landscape-three acres of demonstrations for homeowners and professionals which has been expanded to include the URI Formal Gardens and the Commencement Area. By holding summer meetings of the Nurserymen's Association, the American Society of Landscape Architects, and various homeowner programs such as Master Gardeners and the GreenShare Field Day at these facilities, we shall introduce growers and customers to these plants, hopefully stimulating both production and sales. The R.I. Nurserymen's Association has pledged $80,000 for maintenance of the gardens.

Specific Accomplishments
The first edition of "Sustainable Trees and Shrubs for Southern New England" was released in September, 1993. The second edition was distributed in February, 1995. This publication in its present form is in seven parts. It begins with a discussion of sustainability in landscaping and outlines the purpose of the manual, including a discussion of the role of native species in the sustainable landscape. It then covers planting - including plant selection, handling, installation, irrigation, staking, pruning, fertilization, etc. This section is followed by an index of common names which precedes the plant list.

The list describes approximately 160 useful landscape plants which, to our knowledge, are non-invasive and require reduced inputs of pesticides, water, and maintenance. Plant descriptions include a common and scientific name, USDA hardiness zone, mature size and shape, and a few lines of text on important features or unusual requirements. The guide also includes lists indicating which of the sustainable plants are suited for demanding situations. These are organized under the following headings: drought or dry soils; wet soils or flooding; shade; soil salt, wind, oceanside, roadside, or aerial salt; tolerant of pH 4.5 or lower; tolerant of pH 5.0; tolerant of pH 7.5 or higher; native species; useful beneath power lines; urban conditions; and best planted in spring. The manual ends with a full-page map of USDA plant hardiness zones for the Northeast.

The development of a demonstration landscape received a large boost in 1993 from a donation of approximately $100,000 in plants and labor from the R.I. Nurserymen's Association for a "Learning Landscape" designed and managed by the Cooperative Education Center on the URI campus. This one-acre landscape which surrounds the center is intended to demonstrate the latest in low-maintenance techniques and plant materials for homeowners.

The original "Learning Landscape" represents roughly one-third of the grounds surrounding the URI greenhouses. The remaining land is a formal garden featuring stone walls built in the 1940s. The renovation of this garden into an extension of the Learning Landscape was done between 1993 and 1995.

The major portion of our formal garden which formerly featured square hedges and rectangular annual beds has been totally reworked. Approximately 36 trees of 2.5 inch caliper were installed, primarily around the edges of the garden. Border beds were established for shrubs and perennials. The site was regraded and tilled in preparation for a spring seeding of a low-maintenance lawn of dwarf varieties of endophytic hard and Chewings fescues. The beds were planted with shrubs and perennials in the spring of 1995. The last garden to be planted will contain azaleas and rhododendrons planted in an open deciduous understory.

When complete, the Formal Garden and Learning Landscape will provide an unparalleled opportunity for us to educate the entire community, including students, homeowners, landscape architects and nurserymen, about the use of sustainable plants and designs. Massachusetts nurserymen, inspired by the effort of their Rhode Island colleagues, are presently considering creating a similar demonstration landscape in their state.