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 Certified Soil Testing Labs
Standard Fee: $20 - $35 routine soil 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 Till & Columbia Basin Volcanic Ash
Hardiness Zones: Zone 5a / 9a
Popular Crops: Apples, cherries, hops, berries, wheat, wine grapes
Western Washington soils lean acidic due to rain; Eastern Washington soils tend alkaline.
Featured County Directories in Washington (8 Listings)
King County
Extension Office: Washington State University Extension - King County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Pierce County
Extension Office: Washington State University Extension - Pierce County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Snohomish County
Extension Office: Washington State University Extension - Snohomish County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Spokane County
Extension Office: Washington State University Extension - Spokane County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Clark County
Extension Office: Washington State University Extension - Clark County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Thurston County
Extension Office: Washington State University Extension - Thurston County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Yakima County
Extension Office: Washington State University Extension - Yakima County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
Whatcom County
Extension Office: Washington State University Extension - Whatcom County
Soil Lab Fee: $20 - $35 routine soil sample
Phone: (530) 555-0199
📦 Recommended Mail-In Soil Test Kits & Meters
FTC Affiliate Disclosure: We may earn a commissionIf you need immediate results without waiting for university mail-in lab turnaround times, these top-rated professional home soil test kits provide fast pH, N, P, and K diagnostic analysis:
MySoil Soil Test Kit
Professional mail-in kit analyzed by accredited labs. Returns 13 essential nutrient values (N, P, K, pH, Micronutrients) & customized fertilizer recommendations via app.
Luster Leaf Rapitest 1601
Popular color-comparator kit for 10 instant soil tests (pH, Nitrogen, Phosphorus, Potash). Includes tailored plant preference chart.
Sonkir 3-in-1 Soil Tester
Instant probe sensor for soil moisture, pH, and sunlight levels. Requires no batteries. Perfect for potted plants, lawns, and raised beds.
📋 Request Local Extension & Lawn Testing Assistance in Washington Statewide
Need help interpreting your lab results or finding local agricultural extension agents? Fill out the brief form below:
Frequently 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 Certified Soil Testing Labs or your local county extension office.
How much does soil testing cost in Washington?
Routine soil fertility analysis in Washington typically costs $20 - $35 routine soil 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.