When to Plant Onion in Bourbon County, KS
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.
Bourbon County, Kansas is in USDA Zone 6a. The average last spring frost is April 8 and the first fall frost is October 25, giving you a growing season of approximately 200 days.
At an elevation of 438 feet, Bourbon County receives approximately 26 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Onion during the growing season.
Bourbon County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.2
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Bourbon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Bourbon County, KS
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | April 8 | Apr 8 – Apr 22 |
| Direct Sow | March 25 | Mar 25 – Apr 15 |
| Harvest | July 8 | Jul 8 – Aug 26 |
| Fall Sowing | August 16 | Aug 16 – Aug 30 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| 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
200 days in Bourbon County
Growing Tips for Bourbon 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 Bourbon County, KS?
Bourbon County is in Zone 6a with an average last frost of April 8. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bourbon County, KS?
Bourbon County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 8 and first fall frost is October 25.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Bourbon County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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