When to Plant Potatoes in Adams County, IL
Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.
Adams County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 20, giving you a growing season of approximately 189 days.
At an elevation of 1,390 feet, Adams County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Potatoes during the growing season.
Adams County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.3
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Potatoes Planting Timeline — Adams County, IL
Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 17 | Feb 17 – Mar 3 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | July 7 | Jul 7 – Sep 15 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
70–120 days
Soil pH
5 – 6.5
USDA Zone
Zone 5b
Growing Season
189 days
Growing Tips for Adams County
Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Potatoes in Other Locations
Frequently Asked Questions
When should I plant Potatoes in Adams County, IL?
Adams County is in Zone 5b with an average last frost of April 14. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, IL?
Adams County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 20.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Adams County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.