The King Conservation District has a soil testing program for anyone living within the District boundaries. This includes all of incorporated and unincorporated King County, except for cities that are not members of the King Conservation District: Enumclaw, Federal Way, Milton, Pacific and Skykomish.
Keyword: Soil testing
Environmental Laboratories Accredited by Washington State Dept of Ecology
A list of accredited laboratories that test for toxins and chemicals in soil and water samples.
Garden Tip #185
Successful gardeners know that healthy soil translates to healthy plants. See the guide to soils and fertilizers for the home gardener from WSU Cooperative Extension.
Information Resources for Soil for Gardeners
A list of the best books, articles and websites on soils, soil amendment, composting and mulching.
Amherst, University of Massachusetts, Soil Testing
University of Massachusetts at Amherst’s Soil and Plant Tissue Testing Laboratory (relatively inexpensive)
Soil Test Interpretation Guide
General guidelines for interpreting soil test results from Oregon State University (12 page pdf document)
WSU’s Soils and Soil Testing
From Washington State University. Includes resources on soil testing and soil test interpretation as well as a set of 29 slides that show the major soil types of the Puget Sound area.
A Guide to Collecting Soil Samples for Farms and Gardens
From Oregon State University. This publication gives concise discussions on why, when, and where to collect your soil sample, and straightforward instructions for how to take the soil sample and choose a lab to perform the analysis.