On a cold, February day, King County staff were busy planting native shrubs in one of the County’s most visible parks, Marymoor Park in Redmond. The planting day is part of the Heart of Marymoor Restoration Project, an innovative pilot project to transform a drainage channel into a living laboratory for restoration science with a heart-shaped landscape feature that serves as a symbol of stewardship.
The project, a partnership between King County’s Parks and Solid Waste divisions, will evaluate the benefits of locally produced compost and other materials added to the soil during restoration work.
The project has two major components: converting the heart-shaped patch of turf and invasive reed canary grass into a resilient, low maintenance ecosystem, and using 16 test plots to study a variety of soil treatments and amendments. Each plot tests different combinations of compost, sand, biochar and native soil to evaluate how effectively they support native plant growth. King County staff seeded the test plots this January.
Designed as an accessible public demonstration site, the project will provide multiple benefits:
- Using locally produced compost helps support green jobs, reduce waste and cut greenhouse gas emissions by keeping organic material out of the landfill and turning it into a valuable soil amendment used to restore local ecosystems. Organic materials buried in landfills produce methane — a greenhouse gas 30 times more potent than carbon dioxide.
- The project will also help Parks create sustainable meadows and restoration projects on other properties throughout King County. The work has the potential to reduce the long-term cost and labor of restoration efforts and inform best practices and guidance for ecological landscaping across the region.
- Restoring the existing area with more resilient, native plants will support pollinators and other wildlife.
What’s next for the Heart of Marymoor?
The native shrub planting and seed spreading are just the first step of a multi-year project. The restoration will include additional rounds of planting and seeding as well as ongoing maintenance and monitoring. The meadow test plots will also help Parks evaluate how seeding techniques could be used to manage portions of Parks open space in ways that increase ecological value while maintaining accessible landscapes and supporting efficient stewardship. We’ll continue to provide updates on the project in the coming months. If you want to see the progress for yourself, the Heart of Marymoor is located just off the Marymoor Connector Trail, northeast of Parking Lot G (view location).
This project is part of King County’s Re+ initiative and CompostWise, and is supported by the voter-approved King County Parks Levy. Thank you for your support!
