When to plant onions in Illinois

Plant out in Chicago

Feb 27–Mar 20

Across Illinois the window opens between February 21 and March 20. Find your city below; the dates follow each town's own average last frost.

Start indoors, Chicago: Jan 16–Feb 13
Plant out, Chicago: Feb 27–Mar 20
Last frost, Chicago: Apr 10

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Northern gardens need long-day varieties and southern gardens need short-day ones. A wrong pick gives small bulbs.

Onions planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

JanFebMarAprMayJunJulAugSepOctNovDec

ChicagoFeb 27–Mar 20

AuroraMar 8–Mar 29

NapervilleMar 17–Apr 7

JolietMar 8–Mar 29

RockfordMar 13–Apr 3

ElginMar 15–Apr 5

SpringfieldMar 4–Mar 25

PeoriaMar 5–Mar 26

ChampaignMar 4–Mar 25

WaukeganMar 19–Apr 9

CiceroFeb 28–Mar 21

BloomingtonMar 14–Apr 4

SchaumburgMar 19–Apr 9

EvanstonMar 15–Apr 5

Arlington HeightsMar 8–Mar 29

BolingbrookMar 9–Mar 30

DecaturMar 3–Mar 24

SkokieMar 15–Apr 5

PalatineMar 14–Apr 4

Des PlainesMar 5–Mar 26

Orland ParkMar 8–Mar 29

Oak LawnFeb 27–Mar 20

Mount ProspectMar 8–Mar 29

Tinley ParkMar 12–Apr 2

BerwynFeb 28–Mar 21

WheatonMar 17–Apr 7

NormalMar 14–Apr 4

Oak ParkFeb 28–Mar 21

Hoffman EstatesMar 19–Apr 9

Downers GroveMar 17–Apr 7

All 121 cities

City	Start indoors	Plant out	Last frost
Chicago	Jan 16 to Feb 13	Feb 27 to Mar 20	Apr 10
Aurora	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Naperville	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Joliet	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Rockford	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Elgin	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Springfield	Jan 21 to Feb 18	Mar 4 to Mar 25	Apr 15
Peoria	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Champaign	Jan 21 to Feb 18	Mar 4 to Mar 25	Apr 15
Waukegan	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Cicero	Jan 17 to Feb 14	Feb 28 to Mar 21	Apr 11
Bloomington	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Schaumburg	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Evanston	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Arlington Heights	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Bolingbrook	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Decatur	Jan 20 to Feb 17	Mar 3 to Mar 24	Apr 14
Skokie	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Palatine	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Des Plaines	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Orland Park	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Oak Lawn	Jan 16 to Feb 13	Feb 27 to Mar 20	Apr 10
Mount Prospect	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Tinley Park	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Berwyn	Jan 17 to Feb 14	Feb 28 to Mar 21	Apr 11
Wheaton	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Normal	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Oak Park	Jan 17 to Feb 14	Feb 28 to Mar 21	Apr 11
Hoffman Estates	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Downers Grove	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Plainfield	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Glenview	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Elmhurst	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Lombard	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Buffalo Grove	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Moline	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Crystal Lake	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Romeoville	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Bartlett	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
DeKalb	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Belleville	Jan 18 to Feb 15	Mar 1 to Mar 22	Apr 12
Oswego	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Urbana	Jan 21 to Feb 18	Mar 4 to Mar 25	Apr 15
Carol Stream	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Quincy	Jan 14 to Feb 11	Feb 25 to Mar 18	Apr 8
Park Ridge	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Wheeling	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Streamwood	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Carpentersville	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Hanover Park	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Rock Island	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Addison	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Calumet City	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Northbrook	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
North Chicago	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Woodridge	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
St. Charles	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Mundelein	Feb 4 to Mar 4	Mar 18 to Apr 8	Apr 29
O'Fallon	Jan 18 to Feb 15	Mar 1 to Mar 22	Apr 12
Glendale Heights	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Elk Grove Village	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Pekin	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Algonquin	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Highland Park	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Gurnee	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Niles	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
McHenry	Feb 6 to Mar 6	Mar 20 to Apr 10	May 1
Huntley	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
New Lenox	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Glen Ellyn	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Lake in the Hills	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Galesburg	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Burbank	Jan 16 to Feb 13	Feb 27 to Mar 20	Apr 10
Danville	Jan 27 to Feb 24	Mar 10 to Mar 31	Apr 21
Lansing	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Lockport	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Wilmette	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Round Lake Beach	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Vernon Hills	Feb 4 to Mar 4	Mar 18 to Apr 8	Apr 29
Granite City	Jan 10 to Feb 7	Feb 21 to Mar 14	Apr 4
Oak Forest	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Yorkville	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Batavia	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Chicago Heights	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Edwardsville	Jan 10 to Feb 7	Feb 21 to Mar 14	Apr 4
Woodstock	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
South Elgin	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Belvidere	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
West Chicago	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Alton	Jan 10 to Feb 7	Feb 21 to Mar 14	Apr 4
Homer Glen	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Morton Grove	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Zion	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Westmont	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Melrose Park	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Collinsville	Jan 14 to Feb 11	Feb 25 to Mar 18	Apr 8
Loves Park	Jan 30 to Feb 27	Mar 13 to Apr 3	Apr 24
Rolling Meadows	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Elmwood Park	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Lisle	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Kankakee	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Maywood	Jan 17 to Feb 14	Feb 28 to Mar 21	Apr 11
Freeport	Feb 1 to Mar 1	Mar 15 to Apr 5	Apr 26
Machesney Park	Feb 6 to Mar 6	Mar 20 to Apr 10	May 1
Roselle	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
Bloomingdale	Feb 5 to Mar 5	Mar 19 to Apr 9	Apr 30
East Peoria	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16
Darien	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Montgomery	Jan 25 to Feb 22	Mar 8 to Mar 29	Apr 19
Villa Park	Feb 3 to Mar 3	Mar 17 to Apr 7	Apr 28
Carbondale	Jan 15 to Feb 12	Feb 26 to Mar 19	Apr 9
Blue Island	Jan 16 to Feb 13	Feb 27 to Mar 20	Apr 10
Frankfort	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Grayslake	Feb 4 to Mar 4	Mar 18 to Apr 8	Apr 29
Geneva	Jan 31 to Feb 28	Mar 14 to Apr 4	Apr 25
Park Forest	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
South Holland	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
Libertyville	Feb 4 to Mar 4	Mar 18 to Apr 8	Apr 29
Crest Hill	Jan 26 to Feb 23	Mar 9 to Mar 30	Apr 20
Dolton	Jan 29 to Feb 26	Mar 12 to Apr 2	Apr 23
East Moline	Jan 22 to Feb 19	Mar 5 to Mar 26	Apr 16

Questions

When should I plant onions in Illinois?

In Chicago, plant out from February 27 to March 20. Across Illinois the window opens between February 21 and March 20, depending on the local last frost.

How is this date worked out?

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Illinois

Onions in other states

Frost dates for every city in Illinois