FrostCal

When to Plant Onions in Oklahoma

In a typical Oklahoma location, start seeds indoors Jan 22 – Feb 5, then transplant outdoors Mar 5 – Mar 19. Across the state, the outdoor planting window starts as early as Feb 15 in Ardmore and as late as Mar 21 in Guymon.

Method Start indoors, then transplant
Days to maturity 90–120 days

Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings.

Onions Planting Dates by City

CityStart indoorsTransplant
Oklahoma CityJan 24 – Feb 7Mar 7 – Mar 21
TulsaJan 20 – Feb 3Mar 3 – Mar 17
NormanJan 20 – Feb 3Mar 3 – Mar 17
Broken ArrowJan 21 – Feb 4Mar 4 – Mar 18
LawtonJan 21 – Feb 4Mar 4 – Mar 18
EdmondJan 22 – Feb 5Mar 5 – Mar 19
MooreJan 24 – Feb 7Mar 7 – Mar 21
Midwest CityJan 22 – Feb 5Mar 5 – Mar 19
EnidJan 26 – Feb 9Mar 9 – Mar 23
StillwaterJan 25 – Feb 8Mar 8 – Mar 22
MuskogeeJan 27 – Feb 10Mar 10 – Mar 24
BartlesvilleJan 31 – Feb 14Mar 14 – Mar 28
OwassoJan 20 – Feb 3Mar 3 – Mar 17
ShawneeJan 19 – Feb 2Mar 2 – Mar 16
YukonJan 22 – Feb 5Mar 5 – Mar 19
ArdmoreJan 4 – Jan 18Feb 15 – Mar 1
Ponca CityJan 30 – Feb 13Mar 13 – Mar 27
BixbyJan 21 – Feb 4Mar 4 – Mar 18
DuncanJan 14 – Jan 28Feb 25 – Mar 11
Del CityJan 22 – Feb 5Mar 5 – Mar 19
JenksJan 19 – Feb 2Mar 2 – Mar 16
SapulpaJan 19 – Feb 2Mar 2 – Mar 16
MustangJan 24 – Feb 7Mar 7 – Mar 21
Sand SpringsJan 19 – Feb 2Mar 2 – Mar 16
BethanyJan 22 – Feb 5Mar 5 – Mar 19
AltusJan 25 – Feb 8Mar 8 – Mar 22
ClaremoreJan 27 – Feb 10Mar 10 – Mar 24
El RenoJan 26 – Feb 9Mar 9 – Mar 23
McAlesterJan 20 – Feb 3Mar 3 – Mar 17
AdaJan 22 – Feb 5Mar 5 – Mar 19

Showing the 30 most populous of 48 Oklahoma cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Oklahoma cities.

Frequently Asked Questions

When should I plant onions in Oklahoma?

In a typical Oklahoma location, start seeds indoors Jan 22 – Feb 5, then transplant outdoors Mar 5 – Mar 19. Across the state, the outdoor planting window starts as early as Feb 15 in Ardmore and as late as Mar 21 in Guymon.

When is the last frost in Oklahoma?

The average last spring frost in Oklahoma ranges from March 15 in Ardmore to April 18 in Guymon, based on NOAA 1991–2020 climate normals.

How long do onions take to grow?

Onions typically take 90–120 days from planting to harvest. Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings.

Other Crops in Oklahoma

When to plant onions in other states

Related Guides