California Extension & Soil Testing Directory
Find your local California County Cooperative Extension office, official state university soil analysis lab, and Master Gardener volunteer plant clinics.
🔬 State Soil Testing Laboratory
Official Lab: UC Davis Analytical Laboratory
Standard Fee: $20 routine soil fertility analysis
Turnaround Time: 7 to 10 business days
State residents can obtain soil sample bags and submittal forms at any local county extension branch.
🌱 State Growing Conditions
Soil Types: Central Valley Alluvial Silt Loam & Coastal Clay
Hardiness Zones: Zone 8b / 10b
Popular Crops: Tomatoes, citrus, figs, avocados, stone fruit, cool-season greens
California soils benefit from organic mulch to reduce summer evaporative water loss and manage salinity.
Featured County Directories in California (58 Listings)
Alameda County
Extension Office: University of California (UC ANR) Extension - Alameda County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Alpine County
Extension Office: University of California (UC ANR) Extension - Alpine County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Amador County
Extension Office: University of California (UC ANR) Extension - Amador County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Butte County
Extension Office: University of California (UC ANR) Extension - Butte County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Calaveras County
Extension Office: University of California (UC ANR) Extension - Calaveras County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Colusa County
Extension Office: University of California (UC ANR) Extension - Colusa County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Contra Costa County
Extension Office: University of California (UC ANR) Extension - Contra Costa County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Del Norte County
Extension Office: University of California (UC ANR) Extension - Del Norte County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
El Dorado County
Extension Office: University of California (UC ANR) Extension - El Dorado County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Fresno County
Extension Office: University of California (UC ANR) Extension - Fresno County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Glenn County
Extension Office: University of California (UC ANR) Extension - Glenn County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Humboldt County
Extension Office: University of California (UC ANR) Extension - Humboldt County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Imperial County
Extension Office: University of California (UC ANR) Extension - Imperial County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Inyo County
Extension Office: University of California (UC ANR) Extension - Inyo County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Kern County
Extension Office: University of California (UC ANR) Extension - Kern County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Kings County
Extension Office: University of California (UC ANR) Extension - Kings County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Lake County
Extension Office: University of California (UC ANR) Extension - Lake County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Lassen County
Extension Office: University of California (UC ANR) Extension - Lassen County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Los Angeles County
Extension Office: University of California (UC ANR) Extension - Los Angeles County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Madera County
Extension Office: University of California (UC ANR) Extension - Madera County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Marin County
Extension Office: University of California (UC ANR) Extension - Marin County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Mariposa County
Extension Office: University of California (UC ANR) Extension - Mariposa County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Mendocino County
Extension Office: University of California (UC ANR) Extension - Mendocino County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Merced County
Extension Office: University of California (UC ANR) Extension - Merced County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Modoc County
Extension Office: University of California (UC ANR) Extension - Modoc County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Mono County
Extension Office: University of California (UC ANR) Extension - Mono County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Monterey County
Extension Office: University of California (UC ANR) Extension - Monterey County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Napa County
Extension Office: University of California (UC ANR) Extension - Napa County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Nevada County
Extension Office: University of California (UC ANR) Extension - Nevada County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Orange County
Extension Office: University of California (UC ANR) Extension - Orange County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Placer County
Extension Office: University of California (UC ANR) Extension - Placer County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Plumas County
Extension Office: University of California (UC ANR) Extension - Plumas County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Riverside County
Extension Office: University of California (UC ANR) Extension - Riverside County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Sacramento County
Extension Office: University of California (UC ANR) Extension - Sacramento County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Benito County
Extension Office: University of California (UC ANR) Extension - San Benito County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Bernardino County
Extension Office: University of California (UC ANR) Extension - San Bernardino County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Diego County
Extension Office: University of California (UC ANR) Extension - San Diego County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Francisco County
Extension Office: University of California (UC ANR) Extension - San Francisco County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Joaquin County
Extension Office: University of California (UC ANR) Extension - San Joaquin County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Luis Obispo County
Extension Office: University of California (UC ANR) Extension - San Luis Obispo County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
San Mateo County
Extension Office: University of California (UC ANR) Extension - San Mateo County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Santa Barbara County
Extension Office: University of California (UC ANR) Extension - Santa Barbara County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Santa Clara County
Extension Office: University of California (UC ANR) Extension - Santa Clara County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Santa Cruz County
Extension Office: University of California (UC ANR) Extension - Santa Cruz County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Shasta County
Extension Office: University of California (UC ANR) Extension - Shasta County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Sierra County
Extension Office: University of California (UC ANR) Extension - Sierra County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Siskiyou County
Extension Office: University of California (UC ANR) Extension - Siskiyou County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Solano County
Extension Office: University of California (UC ANR) Extension - Solano County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Sonoma County
Extension Office: University of California (UC ANR) Extension - Sonoma County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Stanislaus County
Extension Office: University of California (UC ANR) Extension - Stanislaus County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (060) 555-0199
Sutter County
Extension Office: University of California (UC ANR) Extension - Sutter County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Tehama County
Extension Office: University of California (UC ANR) Extension - Tehama County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Trinity County
Extension Office: University of California (UC ANR) Extension - Trinity County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Tulare County
Extension Office: University of California (UC ANR) Extension - Tulare County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Tuolumne County
Extension Office: University of California (UC ANR) Extension - Tuolumne County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Ventura County
Extension Office: University of California (UC ANR) Extension - Ventura County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Yolo County
Extension Office: University of California (UC ANR) Extension - Yolo County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 555-0199
Yuba County
Extension Office: University of California (UC ANR) Extension - Yuba County
Soil Lab Fee: $20 routine soil fertility analysis
Phone: (061) 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 California Statewide
Need help interpreting your lab results or finding local agricultural extension agents? Fill out the brief form below:
Frequently Asked Questions: California Soil & Extension
How do I get my soil tested in California?
To test your soil in California, 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 UC Davis Analytical Laboratory or your local county extension office.
How much does soil testing cost in California?
Routine soil fertility analysis in California typically costs $20 routine soil fertility analysis. Turnaround time for results is usually 7 to 10 business days.
Does every county in California have a Cooperative Extension Office?
Yes. Every county in California 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 California.
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.