When to plant Onion in Clinton County, IN
Clinton County gardeners should plant Onion between April 8 and April 29 in spring. With Clinton County's Zone 6a climate (last frost April 22), Onion needs 90–120 days to mature — plant by June 19 for a full harvest. A second sowing from August 8 to August 22 extends the harvest into fall.
When to Plant Onion in Clinton County, IN
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.
Clinton County, Indiana is in USDA Zone 6a. The average last spring frost is April 22 and the first fall frost is October 17, giving you a growing season of approximately 178 days.
At an elevation of 1,116 feet, Clinton County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.
Clinton County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.9
Drainage
Well Drained
Monthly Watering Guide for Onion
Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Onion Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| May | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clinton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Clinton County, IN
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 18 | Mar 18 – Apr 1 |
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Direct Sow | April 8 | Apr 8 – Apr 29 |
| Harvest | July 22 | Jul 22 – Sep 9 |
| 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 | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| 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 6a
📆 Growing Season
178 days in Clinton County
Growing Tips for Clinton 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 Clinton County, IN?
Clinton County is in Zone 6a with an average last frost of April 22. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clinton County, IN?
Clinton County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 22 and first fall frost is October 17.
When should I plant Onion in Clinton County, IN?
In Clinton County, IN, plant Onion after the last frost (around April 22) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Clinton County, IN for Onion?
Clinton County sits in USDA Zone 6a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.
Can Onion grow in Clinton County's climate?
Yes — Onion grows well in Clinton County's temperate climate. Clinton County averages a 178-day frost-free season, with last frost around April 22 and first frost around October 17.
Your Clinton County Garden Planner — Free
A 22-page printable planner built for Clinton County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.