When to Plant Onion in Clark County, AR
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.
Clark County, Arkansas is in USDA Zone 7b. The average last spring frost is March 22 and the first fall frost is November 9, giving you a growing season of approximately 232 days.
At an elevation of 1,350 feet, Clark County receives approximately 45.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Onion during the growing season.
Clark County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.7
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 — Clark County, AR
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Direct Sow | March 8 | Mar 8 – Mar 29 |
| Fall Sowing | August 31 | Aug 31 – Sep 14 |
| Harvest | June 21 | Jun 21 – Aug 9 |
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 | Fall Sowing 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
6 – 7
USDA Zone
Zone 7b
Growing Season
232 days
Growing Tips for Clark 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 Clark County, AR?
Clark County is in Zone 7b with an average last frost of March 22. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, AR?
Clark County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 22 and first fall frost is November 9.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Clark County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.