Sustainable Sites Initiative

Malolepsy/Battershell residence - front yard (Photo by D.Tolman)

Malolepsy/Battershell residence garden

Size & Type of Project:
Approx. 0.11 acre (50 x 100 foot lot)/ Urban Residence; Greyfield

Location:
Portland, Oregon

Budget:
$16,500 (design, materials and labor)

Project Phase:

 Completed in June 2008

Project Overview

The Malolepsy/Battershell project is a small, renovated urban residential landscape in Portland, Oregon. The project objectives included reducing water use for irrigation, managing stormwater runoff, decreasing heat build-up from a concrete driveway, re-using salvaged materials, and increasing water infiltration and productivity of marginal and compacted urban soil. The new landscape design continues to provide approximately 60 percent of the garden vegetables for the Malolepsy/Battershell family diet and created new spaces for family activities such as gardening, dining, and playing. Client and designer goals-such as maintaining bioregional characteristics and involving the family in garden implementation-guided the project in all phases of development.

Site Context

The site is located in the Willamette Valley ecoregion, which was historically covered by rolling prairies, oak savannas, coniferous forests, extensive wetlands, and deciduous riparian forests. Today, it contains the bulk of Oregon's population, industry, commerce, and agriculture. The climate is Mediterranean/marine west coast which is characterized by mild winters and summers. Approximately 45 inches of precipitation falls during 7 months of the year while the remaining 5 months, from June to October, are generally dry. 

The Malolepsy/Battershell site is located in an upper-middle class residential neighborhood of primarily owner-occupied homes. Houses range from 1,400 to 3,000 square feet on 5,000 to 8,000 square-foot lots. Prior to garden implementation, the site was characterized by compacted soil with a 40 percent slope (elevated 10 feet above street level), stormwater runoff directed toward the house and the street, and a lack of shade.

Malolepsy/Battershell residence (Photo by D.Tolman)

Sustainable Practices

Protect existing soils during construction/ Restore disturbed soils: Plans were developed to address soil compaction and the presence of chlordane, a toxic lawn and garden pesticide commonly used to exterminate ants and termites that is damaging to both the environment and human health.
Construction work was confined to designated pathways and the implementation process was staged to reduce additional compaction of the amended soil. No heavy equipment was used on the site.
Soil improvement techniques included amending the soil with 25 cubic yards of compost (applied over existing turf to a depth of 6- to 8 inches) and replanting for quick establishment. An aspen forest (9 clumps of multi-trunked specimens) was designed for the back yard to ameliorate the soil for chlordane contamination in areas where children would be playing. Exposed soil was mulched heavily with neighborhood leaf litter to supplement on-site resources.

Reduce potable water use: Downspouts were disconnected from the residence and two 55-gallon drums were installed to collect rainwater. This both reduced supplemental watering for the landscape and eliminated stormwater runoff from the driveway.
To reduce water needs in the landscape, plants were selected according to site microclimates. A strict and disciplined watering schedule for all plants was implemented, which almost eliminated the need for supplemental potable water in the landscape, including the steepest terrain. Less than 10 percent of total domestic water is used for outside purposes, including the vegetable garden and lawn.

Preserve and restore vegetation: Existing vegetation was retained and incorporated into the new design. An existing maple tree and several existing non-native plants (such as hydrangea, rosemary, and assorted perennials) were incorporated with native ferns and spleenworts, birches, willows, and a couple of species of Ceanothus and Cistus. In the back yard, contiguous nonlinear beds of vegetation with diverse and tiered canopies were strategically placed in order to salvage existing plant material, foster habitat diversity, and create social spaces.

Re-use excess vegetation/ Use salvaged materials: No materials were purchased other than concrete for setting three 4 x 4 posts into the existing driveway for mounting an artistic fence that established the upper quarter of the driveway as useable space. During all phases of construction, landscape waste was recovered and salvaged materials were used.

• Plant trimmings were used as compost.
• Bricks from a decommissioned house chimney were re-used for a large patio and several pathways.
• Broken concrete from the site was used for stepping stones in the garden area and on a pathway in the far back yard which was previously unused space.
• Salvaged wood was re-used for the artistic fence.
• Drawers from an old chest were used as containers for vegetable starts particularly at risk from slugs and water and soil runoff.
• A drywell was constructed in the back yard underneath the lawn and filled with a previously broken up and removed small concrete slab.

Enhance group and individual experiences: The landscape design included spaces or small outdoor "rooms" to accommodate activities on all sides of the house and to promote free flow of child play from front yard to back. A small playhouse connects to the back patio and side path, doubling as a trellis and shade structure. A winding path connects all outdoor rooms, including the gardening room, making them easily accessible. Focal points were created in the landscape for views from inside the house. Although grass was requested in the back yard (for children), multiple microclimates were created for diversity of habitat and plant material. The grass area is large enough to accommodate three children and two parents but small enough to mow with a push mower.

Reduce urban heat island impacts: Shade was established over the driveway and southwest-facing side of the house. Portions of the driveway were converted to a container garden with furniture and rain barrels to help mitigate other heat effects.

Reduce emissions: Hand tools were used during all phases of construction, including the breaking up of the concrete, with one small exception-a power saw was used for three of the four fence posts. Maintenance will continue to avoid the use of machinery.

Construction Cost

Of the $16,500 total cost, the majority was spent on plant material, soil, sand, and landscape design. All other materials came from the site, were found, or were donated by the neighborhood. Labor costs were $4,500. Additional labor was contributed by the homeowner (drywell construction, digging, grading, planting, and mulching), following instruction by the project designer who provided hands-on tutoring and thereby facilitated more homeowner involvement in the finished product. The costs of the sustainable strategies in this project may be lower than conventional practices primarily due to on-site reuse of materials and owner labor contributions.

Monitoring Information

To date, the garden design has been successfully implemented and the homeowners are pleased with the results. The front yard was completed first and has gone through two full growing seasons while an additional year was used to complete the back yard. Field tests of the soil structure have shown that compost has improved the existing soil.

Maintenance

Because most of the design was intended for no- to low-maintenance plantings (with the exception of the vegetable garden), a basic maintenance plan was provided and is currently being followed. During establishment (over the course of 12 months), maintenance and management strategies included weeding in the back yard (2- to 3 hours per season) and deep watering during the dry season (June to October). In the second year there was less weeding and watering as plants were established and covered more ground. In 2007, only one watering was required in the front yard during the dry season. Environmental testing for soil quality was recommended to the homeowner for two years after project completion. In addition to mulching in the spring and fall, the maintenance plan includes adding compost in the garden and to the landscape areas. All fertilization is natural, through leaf litter and compost.

With annual visits by the designer, the Malolepsy/Battershell family is continuing the development of the landscape (i.e. applying mulch, composting, harvesting, replanting of vegetables, espaliering of fruit trees, and watering of containers in driveway with captured rainwater).

Malolepsy/Battershell residence - backyard (Photo by D.Tolman)

Issues/Constraints of the Site

• Accommodating a large garden into a tight urban lot was challenging.
• A neighbor's large ash tree fell during a windstorm at the inception of this project and completely covered the back yard. The homeowners were persuaded, with significant effort, to turn the fallen tree into an opportunity. As much of the tree as possible was salvaged and worked into the landscape design. Any remainder was used for building a wattle fence, as firewood in the household fireplace, and as brown material to provide the carbon for the three compost bins that reside in the yard.
• The site was prone to excessive stormwater runoff because of compacted soil as well as the steep terrain both on-site and in neighbors' yards. The concrete driveway directed runoff either toward the basement of the house or immediately into the street.
• Weeds in the back yard were six feet high and occupied 80 percent of the open space. Weeding maintenance will be required for one to two years in order to exhaust the weeds altogether.
• The disturbed soil-whether bare, compacted, or contaminated with chlordane-needed to be restored.
• The lack of shade trees exacerbated stormwater runoff and contributed to the heat produced from the street, sidewalks, and the driveway.

Lessons Learned

• The rainwater collection system has resolved two issues: 1) reducing potable water needs for landscape irrigation and 2) eliminating stormwater runoff from the driveway.
• The landscape designer's hands-on tutoring may be a successful practice given the homeowners' current involvement.
• Despite the continued successes of the landscape designer's sustainable practices, by far the greatest challenge continues to be the education and communication of how and why natural systems work.

More project details

No website is available at the current time.

Project Consultants

Landscape Designer
Avant Gardens, nw
Deborah Tolman