FrostCal

When to Plant Onions in Missouri

In a typical Missouri location, start seeds indoors Jan 28 – Feb 11, then transplant outdoors Mar 11 – Mar 25. Across the state, the outdoor planting window starts as early as Feb 26 in Sikeston and as late as Mar 24 in Kirksville.

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
Kansas CityJan 24 – Feb 7Mar 7 – Mar 21
St. LouisJan 21 – Feb 4Mar 4 – Mar 18
SpringfieldJan 24 – Feb 7Mar 7 – Mar 21
ColumbiaJan 25 – Feb 8Mar 8 – Mar 22
IndependenceJan 30 – Feb 13Mar 13 – Mar 27
Lee's SummitFeb 2 – Feb 16Mar 16 – Mar 30
O'FallonJan 29 – Feb 12Mar 12 – Mar 26
Saint JosephFeb 8 – Feb 22Mar 22 – Apr 5
Saint CharlesJan 28 – Feb 11Mar 11 – Mar 25
Blue SpringsJan 27 – Feb 10Mar 10 – Mar 24
Saint PetersJan 29 – Feb 12Mar 12 – Mar 26
FlorissantJan 22 – Feb 5Mar 5 – Mar 19
JoplinJan 29 – Feb 12Mar 12 – Mar 26
ChesterfieldJan 24 – Feb 7Mar 7 – Mar 21
Jefferson CityJan 28 – Feb 11Mar 11 – Mar 25
Cape GirardeauJan 25 – Feb 8Mar 8 – Mar 22
OakvilleJan 26 – Feb 9Mar 9 – Mar 23
WildwoodFeb 1 – Feb 15Mar 15 – Mar 29
WentzvilleJan 30 – Feb 13Mar 13 – Mar 27
University CityJan 21 – Feb 4Mar 4 – Mar 18
BallwinJan 24 – Feb 7Mar 7 – Mar 21
LibertyFeb 8 – Feb 22Mar 22 – Apr 5
RaytownJan 30 – Feb 13Mar 13 – Mar 27
MehlvilleJan 26 – Feb 9Mar 9 – Mar 23
KirkwoodJan 21 – Feb 4Mar 4 – Mar 18
Maryland HeightsJan 22 – Feb 5Mar 5 – Mar 19
GladstoneJan 24 – Feb 7Mar 7 – Mar 21
HazelwoodJan 22 – Feb 5Mar 5 – Mar 19
GrandviewJan 27 – Feb 10Mar 10 – Mar 24
Webster GrovesJan 21 – Feb 4Mar 4 – Mar 18

Showing the 30 most populous of 90 Missouri cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Missouri cities.

Frequently Asked Questions

When should I plant onions in Missouri?

In a typical Missouri location, start seeds indoors Jan 28 – Feb 11, then transplant outdoors Mar 11 – Mar 25. Across the state, the outdoor planting window starts as early as Feb 26 in Sikeston and as late as Mar 24 in Kirksville.

When is the last frost in Missouri?

The average last spring frost in Missouri ranges from March 26 in Sikeston to April 21 in Kirksville, 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 Missouri

When to plant onions in other states

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