Washington County, OR Extension Office & Soil Testing Directory
Welcome to the official directory resource for Washington County, OR. Connecting local homeowners, urban gardeners, and commercial growers with Oregon's land-grant university extension resources, state soil testing lab services, and Master Gardener volunteer clinics.
1. Extension Office Contact Details & Operational Hours
The Oregon State University Extension - Washington County serves as the primary educational extension center in Washington County. Visit or call during standard operational hours for agricultural advice, soil sample kits, and youth 4-H programs.
| Official Office Name: | Oregon State University Extension - Washington County |
| Physical Address: | Hillsboro, Oregon 97123 |
| Direct Phone Desk: | (410) 555-0199 |
| Email Contact: | washington@oregonstate.edu |
| Office Hours: | Monday – Friday: 8:00 AM – 4:30 PM |
| Official Web Portal: | https://extension.oregonstate.edu/ |
2. Official Soil Testing Laboratory & Pricing
Testing your soil is the single most important step before adding fertilizers or agricultural lime. The official testing laboratory serving Washington County is OSU Extension Recommended Soil Laboratories.
| Official Testing Lab: | OSU Extension Recommended Soil Laboratories |
| Lab Location: | Submittal details available at local county extension office |
| Routine Sample Fee: | $20 - $30 routine soil sample |
| Expected Turnaround: | 5 to 7 business days |
| Official Lab Website: | https://extension.oregonstate.edu/ |
How to Collect and Submit a Soil Sample in Washington County:
- Pick up a Soil Kit: Pick up official sample boxes and submittal forms at the Oregon State University Extension - Washington County (Hillsboro, Oregon 97123).
- Collect Sub-Samples: Use a clean stainless steel trowel to take 10 to 12 soil cores from a 4-to-6-inch depth across your garden or lawn area.
- Air-Dry: Mix sub-samples in a clean plastic bucket and air-dry on clean paper at room temperature (never use an oven).
- Submit Sample: Return your filled soil box to the extension office or mail directly to OSU Extension Recommended Soil Laboratories.
3. Master Gardener Volunteer Program & Plant Clinic
The Washington County Extension Master Gardener Volunteers provides free plant disease diagnostics, lawn care advice, and eco-friendly pest management tips.
| Program Name: | Washington County Extension Master Gardener Volunteers |
| Plant Clinic Hours: | Tuesday & Thursday: 9:00 AM – 12:00 PM (Note: Plant clinics run seasonally; call office during winter months) |
| Direct Helpline Phone: | (410) 555-0199 |
| Program Portal: | https://extension.oregonstate.edu/ |
Volunteer Training: Comprehensive horticulture training conducted by Oregon State University Extension.
4. Regional Soil & Growing Snapshot for Washington County
USDA Plant Hardiness Zone: Zone 5a / 9a
Natural Soil Profile: Willamette Valley Silt Loam & Volcanic Clay
Popular Local Crops: Hazelnuts, berries, hops, wine grapes, turf seed
Extension Specialist Tip: Pacific Northwest winter rain leaches calcium and magnesium; test soil every two years.
5. 🧮 Interactive Soil Amendment Calculator for Washington County
Estimate the recommended agricultural limestone or elemental sulfur needed to adjust your garden soil pH based on local Willamette Valley Silt Loam & Volcanic Clay characteristics.
📚 Recommended Extension Guides & Soil Articles
Learn more about interpreting your Washington County extension soil test report and managing plant nutrients:
📦 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 County, OR
Need help interpreting your lab results or finding local agricultural extension agents? Fill out the brief form below:
Frequently Asked Questions (Washington County Directory)
The Oregon State University Extension - Washington County is located at Hillsboro, Oregon 97123. You can call their main desk directly at (410) 555-0199 during standard business hours (Monday – Friday: 8:00 AM – 4:30 PM).
Standard soil analysis for Washington County garden samples through OSU Extension Recommended Soil Laboratories costs $20 - $30 routine soil sample. Check with the office for special sample types.
You can reach the Washington County Extension Master Gardener Volunteers hotline by calling (410) 555-0199 during plant clinic hours (Tuesday & Thursday: 9:00 AM – 12:00 PM).
Washington County falls primarily within USDA Plant Hardiness Zone 5a / 9a. Local soil is characterized as Willamette Valley Silt Loam & Volcanic Clay.
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.