FrostCal

When to Plant Thyme in Illinois

In a typical Illinois location, start seeds indoors Feb 23 – Mar 9, then transplant outdoors Apr 20 – Apr 27. Across the state, the outdoor planting window starts as early as Apr 1 in Granite City and as late as May 1 in Roscoe.

Method Start indoors, then transplant
Days to maturity 85–95 days

Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost.

Thyme Planting Dates by City

CityStart indoorsTransplant
ChicagoFeb 13 – Feb 27Apr 10 – Apr 17
AuroraFeb 22 – Mar 8Apr 19 – Apr 26
RockfordFeb 27 – Mar 13Apr 24 – May 1
JolietFeb 22 – Mar 8Apr 19 – Apr 26
NapervilleMar 3 – Mar 17Apr 28 – May 5
PeoriaFeb 19 – Mar 5Apr 16 – Apr 23
SpringfieldFeb 18 – Mar 4Apr 15 – Apr 22
North PeoriaFeb 19 – Mar 5Apr 16 – Apr 23
ElginMar 1 – Mar 15Apr 26 – May 3
WaukeganMar 5 – Mar 19Apr 30 – May 7
ChampaignFeb 18 – Mar 4Apr 15 – Apr 22
CiceroFeb 14 – Feb 28Apr 11 – Apr 18
BloomingtonFeb 24 – Mar 10Apr 21 – Apr 28
Arlington HeightsFeb 22 – Mar 8Apr 19 – Apr 26
EvanstonMar 1 – Mar 15Apr 26 – May 3
SchaumburgMar 5 – Mar 19Apr 30 – May 7
BolingbrookFeb 23 – Mar 9Apr 20 – Apr 27
DecaturFeb 17 – Mar 3Apr 14 – Apr 21
PalatineFeb 28 – Mar 14Apr 25 – May 2
SkokieMar 1 – Mar 15Apr 26 – May 3
Des PlainesFeb 19 – Mar 5Apr 16 – Apr 23
Orland ParkFeb 22 – Mar 8Apr 19 – Apr 26
Tinley ParkFeb 26 – Mar 12Apr 23 – Apr 30
Oak LawnFeb 13 – Feb 27Apr 10 – Apr 17
BerwynFeb 14 – Feb 28Apr 11 – Apr 18
Mount ProspectFeb 22 – Mar 8Apr 19 – Apr 26
NormalFeb 28 – Mar 14Apr 25 – May 2
WheatonMar 3 – Mar 17Apr 28 – May 5
Oak ParkFeb 14 – Feb 28Apr 11 – Apr 18
Hoffman EstatesMar 5 – Mar 19Apr 30 – May 7

Showing the 30 most populous of 242 Illinois cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Illinois cities.

Frequently Asked Questions

When should I plant thyme in Illinois?

In a typical Illinois location, start seeds indoors Feb 23 – Mar 9, then transplant outdoors Apr 20 – Apr 27. Across the state, the outdoor planting window starts as early as Apr 1 in Granite City and as late as May 1 in Roscoe.

When is the last frost in Illinois?

The average last spring frost in Illinois ranges from April 1 in Granite City to May 1 in Roscoe, based on NOAA 1991–2020 climate normals.

How long do thyme take to grow?

Thyme typically take 85–95 days from planting to harvest. Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost.

Other Crops in Illinois

When to plant thyme in other states

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