When to plant Onion in Effingham County, IL
Onion planted in Effingham County between April 2 and April 23 matures in 90–120 days — well before the October 17 first frost. A second sowing from August 8 to August 22 extends the harvest into fall.
When to Plant Onion in Effingham County, IL
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
Effingham County, Illinois is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 17, giving you a growing season of approximately 184 days.
At an elevation of 953 feet, Effingham County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Onion to ensure they mature before fall.
Effingham County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Onion Planting Timeline — Effingham County, IL
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 12 | Mar 12 – Mar 26 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Direct Sow | April 2 | Apr 2 – Apr 23 |
| Harvest | July 16 | Jul 16 – Sep 3 |
| Fall Sowing | August 8 | Aug 8 – Aug 22 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
184 days in Effingham County
Growing Tips for Effingham County
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Effingham County, IL?
Effingham County is in Zone 6b with an average last frost of April 16. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Effingham County, IL?
Effingham County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 17.
When should I plant Onion in Effingham County, IL?
In Effingham County, IL, plant Onion after the last frost (around April 16) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Effingham County, IL for Onion?
Effingham County sits in USDA Zone 6b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Effingham County's climate?
Yes — Onion grows well in Effingham County's temperate climate. Effingham County averages a 184-day frost-free season, with last frost around April 16 and first frost around October 17.
Your Effingham County Garden Planner — Free
A 22-page printable planner built for Effingham County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.