Cook County, IL Extension Office & Soil Testing Directory
Welcome to the official directory resource for Cook County, IL. Connecting local homeowners, urban gardeners, and commercial growers with Illinois's land-grant university extension resources, state soil testing lab services, and Master Gardener volunteer clinics.
1. Extension Office Contact Details & Operational Hours
The University of Illinois Extension - Cook County serves as the primary educational extension center in Cook County. Visit or call during standard operational hours for agricultural advice, soil sample kits, and youth 4-H programs.
| Official Office Name: | University of Illinois Extension - Cook County |
| Physical Address: | 17314 S. Oak Park Ave, Tinley Park, IL 60477 |
| Direct Phone Desk: | (708) 449-4320 |
| Email Contact: | ui-extension@illinois.edu |
| Office Hours: | Monday – Friday: 8:00 AM – 4:30 PM |
| Official Web Portal: | https://extension.illinois.edu/cook |
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 Cook County is STAT Analysis Accredited Laboratory Partner.
| Official Testing Lab: | STAT Analysis Accredited Laboratory Partner |
| Lab Location: | 2224 W Harrison St, Suite 200, Chicago, IL 60612 |
| Routine Sample Fee: | $25 routine garden soil sample |
| Expected Turnaround: | 5 to 7 business days |
| Official Lab Website: | https://extension.illinois.edu/soil-testing |
How to Collect and Submit a Soil Sample in Cook County:
- Pick up a Soil Kit: Pick up official sample boxes and submittal forms at the University of Illinois Extension - Cook County (17314 S. Oak Park Ave, Tinley Park, IL 60477).
- 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 STAT Analysis Accredited Laboratory Partner.
3. Master Gardener Volunteer Program & Plant Clinic
The Cook County Master Gardeners provides free plant disease diagnostics, lawn care advice, and eco-friendly pest management tips.
| Program Name: | Cook County Master Gardeners |
| Plant Clinic Hours: | Monday & Thursday: 10:00 AM – 2:00 PM (Note: Plant clinics run seasonally; call office during winter months) |
| Direct Helpline Phone: | (708) 449-4320 |
| Program Portal: | https://extension.illinois.edu/cook/master-gardeners |
Volunteer Training: 60 hours of U of I Extension online & classroom training.
4. Regional Soil & Growing Snapshot for Cook County
USDA Plant Hardiness Zone: Zone 6a
Natural Soil Profile: Rich Prairie Mollisols & Silt Loam
Popular Local Crops: Sweet corn, tomatoes, pumpkins, brassicas, turf grass
Extension Specialist Tip: Illinois prairie soils are fertile; test soil annually to optimize organic matter levels.
5. 🧮 Interactive Soil Amendment Calculator for Cook County
Estimate the recommended agricultural limestone or elemental sulfur needed to adjust your garden soil pH based on local Rich Prairie Mollisols & Silt Loam characteristics.
📚 Recommended Extension Guides & Soil Articles
Learn more about interpreting your Cook County extension soil test report and managing plant nutrients:
Frequently Asked Questions (Cook County Directory)
The University of Illinois Extension - Cook County is located at 17314 S. Oak Park Ave, Tinley Park, IL 60477. You can call their main desk directly at (708) 449-4320 during standard business hours (Monday – Friday: 8:00 AM – 4:30 PM).
Standard soil analysis for Cook County garden samples through STAT Analysis Accredited Laboratory Partner costs $25 routine garden soil sample. Check with the office for special sample types.
You can reach the Cook County Master Gardeners hotline by calling (708) 449-4320 during plant clinic hours (Monday & Thursday: 10:00 AM – 2:00 PM).
Cook County falls primarily within USDA Plant Hardiness Zone 6a. Local soil is characterized as Rich Prairie Mollisols & Silt Loam.
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.