When to Plant Onion in Shannon County, MO
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.
Shannon County, Missouri is in USDA Zone 6a. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.
At an elevation of 1,311 feet, Shannon County receives approximately 35.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Onion during the growing season.
Shannon County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.1
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
Onion Planting Timeline — Shannon County, MO
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 8 | Mar 8 – Mar 22 |
| Transplant Outdoors | April 12 | Apr 12 – Apr 26 |
| Direct Sow | March 29 | Mar 29 – Apr 19 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
| Harvest | July 12 | Jul 12 – 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
6 – 7
USDA Zone
Zone 6a
Growing Season
191 days
Growing Tips for Shannon 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
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Shannon County, MO?
Shannon County is in Zone 6a with an average last frost of April 12. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Shannon County, MO?
Shannon County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 12 and first fall frost is October 20.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Shannon County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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