Gardening in Western Washington - http://gardening.wsu.edu/text/nvintro.htm
This site from Washington State University is devoted to identifying and propagating native plants, which often attract a wider variety of native animals than do exotic plants. Links provide additional information on a number of topics, including stewardship gardening.
King County Yard and Garden Resources - http://dnr.metrokc.gov/topics/yard-and-garden/index.htm
Provides information and programs related to environmentally friendly gardening and yard care. Find information on safer gardening and pest control, how to identify noxious weeks as well as a Northwest Native Plant Guide.
Landscaping With Native Plants: Green Landscaping - http://www.epa.gov/greenacres
Find tips on how to fill your yard, garden, or other open space with plants that grow wild in your area. This will save you money on fertilizer and also benefits the environment. This site is from the U.S. Environmental Protection Agency.
Native Plant Professionals List - http://www.wnps.org/landscaping/documents/landscape_professionals.pdf
Find a list of members of the Washington Native Plant Society, many of whom are Native Plant Stewards. Members on the list may be able to provide professional input on landscaping projects.
Washington Native Plant Society - http://www.wnps.org/
The Washington Native Plant Society is a nonprofit volunteer organization that provides botanical expertise and opportunities for all to share in the enjoyment of Washington's native flora. The Society participates in research about and conservation of Washington's native plants and ecosystems.