Washington Extension & Soil Testing Directory
Find your local Washington County Cooperative Extension office, official state university soil analysis lab, and Master Gardener volunteer plant clinics.
🔬 State Soil Testing Laboratory
Official Lab: WSU Recommended Regional Soil Testing Partner Labs
Standard Fee: $20 – $25 per sample
Turnaround Time: 5 to 7 business days
State residents can obtain soil sample bags and submittal forms at any local county extension branch.
🌱 State Growing Conditions
Soil Types: Puget Sound Glacial Silt and Gravelly Sandy Loam
Hardiness Zones: Zone 8b / 9a
Popular Crops: Berries, apples, brassicas, cool-season greens, turf
Pacific Northwest rainy winters leach soil nutrients; apply organic mulch and test pH every 2 years.
Featured County Directories in Washington (1 Listing)
King County
Extension Office: WSU Extension - King County
Soil Lab Fee: $20 – $25 per sample
Phone: (206) 263-1919
Looking for Another County in Washington?
Every county in Washington is supported by the state Land-Grant University Extension system. If your specific county directory is currently being indexed, you can submit your soil samples directly to WSU Recommended Regional Soil Testing Partner Labs or contact our editorial desk for direct local office hours.
Request Local Extension Info for Your CountyFrequently Asked Questions: Washington Soil & Extension
How do I get my soil tested in Washington?
To test your soil in Washington, collect 10 to 12 soil cores from a depth of 4 to 6 inches across your garden or field, air-dry the sample indoors, fill out your county extension submission form, and submit it to WSU Recommended Regional Soil Testing Partner Labs or your local county extension office.
How much does soil testing cost in Washington?
Routine soil fertility analysis in Washington typically costs $20 – $25 per sample. Turnaround time for results is usually 5 to 7 business days.
Does every county in Washington have a Cooperative Extension Office?
Yes. Every county in Washington is served by the state's Land-Grant University Extension system. While our directory highlights primary regional office hubs and university labs, local extension agents serve horticulturists, farmers, and home gardeners across all counties in Washington.
Written & Verified by Sahajul
Verified Author & Founder
Sahajul is an independent agricultural data researcher based in India and founder of LocalSoilLab.com. He specializes in compiling, structuring, and verifying US land-grant university extension services, soil lab testing fee schedules, and county Master Gardener contact directories directly from official .edu and USDA NIFA portals.