Leach Botanical Garden: Revitalized by

2023 Other / Oregon / USA / Built in 2021 /

The first $12.6 phase of redevelopment of Leach Botanical Garden gives visitors new reasons to visit this 17-acre botanic garden owned by Portland Parks and Recreation in Oregon. After initially developing an ambitious master influenced by public input, owner and team collaboration, and strong strategic thinking, the design team moved forward with phase one of the plan. The first phase offers a tree walk elevated 35-feet, pollinator meadow, gathering green, pavilion with fireside terrace, new paths and connecting trails, entry courtyard, restroom, utilities infrastructure for future development, parking, and sustainable stormwater features. The project honors the legacy of John and Lilla Leach, who founded the garden, and ensures future viability for the garden by providing a secure foundation for growth and visitation.

Design Solution

The first phase embraces the new vision for the garden by developing the upper garden and establishing connections between it and the lower garden. Integral to the garden’s reimaged future is the elevated tree walk, which immerses the visitor in the Pacific Northwest forest. The design also respects the garden’s historic and highly-regarded plant collection.

This phase provides a new system of trails and stairs that reorganizes the garden experience. The 400-foot-long aerial tree walk passes through a native forest of western cedars and Douglas firs. The elevated elliptical-shaped tree walk varies in width, creating spaces for outdoor classrooms or special events. Twenty-seven structural columns support the structure.

A half-acre Pollinator Meadow adjacent to the gathering green features 240 unique taxa. The meadow creates an ecology that attracts pollinating insects and birds to be viewed and interpreted for visitors.

The new fireside terrace anchors each end of the tree walk and features a pavilion structure for holding special events. A fire feature carved from granite serves as a central place for gathering; creating informal classroom space and rental opportunities. Other features include site improvements and infrastructure, such as all utilities for future phases, stormwater management, entry area, parking, and restrooms.

Spatial and Social Facts

Situated in an underserved neighborhood southeast of Portland, the revitalized botanic garden serves as an oasis of green for a community short on greenspace.

The design preserves and brings forward the environmental values of the garden’s founders, John and Lilla Leach, who transformed a five-acre former lumber mill into a collection of 3,000 native and exotic species from the 1930s to early 1970s. As the City acquired additional adjacent acreage over the years, a strategic plan addressing admissions and programming for educational and other events was necessary to ensure financial viability of the garden. The strategic plan responds to those needs; this first phase enacts the plan.

The uniqueness of the tree walk feature, along with the other new elements, creates many reasons for visiting the garden. The elevated walk offers a soaring view and quiet cathedral-like experience that integrates the visitor high into the forest.

Environmental Context

Phase one expanded the plant collection with the addition of the environmentally friendly pollinator meadow and the restored hillside’s native plantings in a sensitive area.
With the creation of visitor-friendly spaces such as the tree walk, pavilion, and fireside terrace, the project refocuses people’s relationship to plants.

Green stormwater features in the new parking areas treat pollutants and are planted in an aesthetically pleasing manner. The pollinator meadow attracts wildlife and provides educational opportunities for visitors.

Gabion site walls are constructed from cobbles found on site.

The revitalization project ensures a strong future for the garden; protecting rare plant collections, creating habitat for plants and animals, and drawing visitors in. Educational opportunities for residents abound.

Merit of Project

Inspired by the filtering of light through statuesque Douglas fir trees on the forested hillside, the design team developed new ways to experience Leach Botanical Garden.

Phase one is a result of thinking big – the consultant was initially hired to create a plan for more parking. Thinking about the bigger picture led the design team to design elements that modernize a formerly languishing garden, setting it up for financial stability and future growth.

Elegant design elements fit the garden’s setting. The steel-fabricated tree walk is graceful and touches lightly on the land. A nearly transparent lath structure provides shelter from the elements for special events. Wood, stone, and steel were selected for durability and aesthetics.

The garden and its design process offer an important lesson to designers: programming elements are key to project’s success. The best parking lot will not ensure visitation. Creating a compelling reason to come is still a best practice.

Architecture offices involved in the design:
Olson Kundig

Team Members
Land Morphology (prime consultant and landscape architecture)
Olson Kundig (architecture)
Reyes Engineering
Janet Turner Engineering, LLC
Lund Opsahl LLC
Morgan Holen and Associates LLC
Mitali and Associates
Northwest Geotech, Inc.

Location: 6704 SE 122nd Ave, Portland, OR 97236, Portland, OR

Design year:

Year Completed:

Main Photo Credits: Aaron Leitz


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