When to Plant Onion in Marshall County, OK
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.
Marshall County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.
At an elevation of 520 feet, Marshall County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Onion during the growing season.
Marshall County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 | — | 0.5" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Apr | 4.3" | 2.3" | 2" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Jul | 4.3" | 3" | 1.3" | 💧 Light watering |
| Aug | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Sep | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Oct | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Nov | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Marshall County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion Planting Timeline — Marshall County, OK
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 17 | Feb 17 – Mar 3 |
| Transplant Outdoors | March 24 | Mar 24 – Apr 7 |
| Direct Sow | March 10 | Mar 10 – Mar 31 |
| Harvest | June 23 | Jun 23 – Aug 11 |
| Fall Sowing | September 3 | Sep 3 – Sep 17 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| 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 8a
📆 Growing Season
233 days in Marshall County
Growing Tips for Marshall 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 Marshall County, OK?
Marshall County is in Zone 8a with an average last frost of March 24. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, OK?
Marshall County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 12.
Your Marshall County Garden Planner — Free
A 22-page printable planner built for Marshall County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.