Ezina · A Field Manual for Plant Care · United States Vol. I · Ed. 2027 · Proof copy

§ When to plant · Illinois · Checked Sept 2026

When to plant vegetables in Illinois

In Chicago, tender crops like tomatoes and peppers can go out around April 25, and frost has historically passed 9 years in 10 by May 9. Cool-season crops go in from March, and again from July for fall.

Get a lifelong price reduction if you join Early Access. iPhone and Android, in the contiguous U.S.

§ 010 · Frost dates

Frost dates across Illinois

Based on NOAA's 1991–2020 station records, with adjustments for tender crops.

City · NOAA stationLast frost, on averagePlant tender crops fromFrost is over, 9 of 10 years byFall frost possible from
Arlington HeightsCHICAGO PALWAUKEE AIRPORT · 7 kmApr 19May 2May 2May 15Oct 13
AuroraAURORA · 2 kmApr 19May 4May 4May 19Oct 9
BloomingtonNORMAL 4NE · 8 kmApr 25May 9May 9May 22Oct 2
BolingbrookROMEOVILLE WFO · 9 kmApr 20May 4May 4May 17Oct 7
ChampaignCHAMPAIGN 3S · 4 kmApr 15Apr 28April 28May 10Oct 11
ChicagoCHICAGO NORTHERLY IS · 7 kmApr 10Apr 25April 25May 9Oct 24
CiceroCHICAGO MIDWAY AIRPORT · 7 kmApr 11Apr 25April 25May 8Oct 20
DecaturDECATUR WTP · 3 kmApr 14Apr 29April 29May 13Oct 11
Des PlainesCHICAGO OHARE INTERNATIONAL AIRPORT · 5 kmApr 16Apr 30April 30May 13Oct 15
ElginELGIN · 4 kmApr 26May 10May 10May 24Oct 3
EvanstonCHICAGO BOTANIC GARDEN · 13 kmApr 26May 11May 11May 26Oct 5
JolietJOLIET BRANDON RD DAM · 4 kmApr 19May 4May 4May 18Oct 12
NapervilleLISLE-MORTON ARBORETUM · 10 kmApr 28May 12May 12May 25Oct 1
PalatineBARRINGTON 3SW · 10 kmApr 25May 10May 10May 25Oct 5
PeoriaPEORIA GTR PEORIA AIRPORT · 11 kmApr 16Apr 30April 30May 14Oct 9
RockfordROCKFORD GTR ROCKFORD AIRPORT · 8 kmApr 24May 7May 7May 19Oct 2
SchaumburgSTREAMWOOD · 8 kmApr 30May 15May 15May 29Sep 29
SkokieCHICAGO BOTANIC GARDEN · 12 kmApr 26May 11May 11May 26Oct 5
SpringfieldSPRINGFIELD #2 · 3 kmApr 15Apr 29April 29May 13Oct 9
WaukeganWAUKEGAN · 2 kmApr 30May 14May 14May 27Sep 30

Illinois's 20 largest cities (U.S. Census Bureau 2025 estimates), A to Z, each with its nearest NOAA station and the distance to it. Search any town to get its nearest station. "Plant tender crops from" is halfway between the average last frost and the date frost is over 9 years in 10; if frost is in the forecast after it, wait until it passes and nights stay above 36°F.

§ 020 · What to plant

What to plant in Illinois, and when

Planting windows from Illinois's Cooperative Extension Service. Filter by season or crop group; every view has its own link.

Region
Season
Crops
  • Dark green: fall planting window
  • Light green: spring and summer planting window
  • TenderKilled by frost: spring planting from the "plant tender crops from" date for your city

§ 030 · Crop by crop

Planting in Illinois

Each crop has its own link, like #tomatoes. Tender crops wait for the frost dates above; succession crops are sown again every few weeks for a steady harvest.

  • Dark green: fall planting window
  • Light green: spring and summer planting window

Asparagus

Asparagus officinalis

Perennial
Asparagus
Photo by Evelyn Simak / CC BY-SA 2.0 / Wikimedia Commons

Northern Illinois: plant Apr.
Central Illinois: plant Mar–Apr.
Southern Illinois: plant Mar–Apr.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Beets

Beta vulgaris

Cool seasonSuccession sow
Beets
Photo by W.carter / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow Apr–Jul.
Central Illinois: sow Apr–Jul.
Southern Illinois: sow Mar–Jul.

Ready in about 58 days; sow again every 6 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Broccoli

Brassica oleracea

Cool season
Broccoli
Photo by Kolforn / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: set out transplants Apr–May, and again Jul.
Central Illinois: set out transplants Apr–May, and again Jul.
Southern Illinois: set out transplants Mar–Apr, and again Jul.

Ready in about 95 days from seed, 65 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Cabbage

Brassica oleracea

Cool season
Cabbage
Photo by Biswarup Ganguly / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: set out transplants Apr–Jul.
Central Illinois: set out transplants Apr–Jul.
Southern Illinois: set out transplants Mar–Jul.

Ready in about 110 days from seed, 80 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Cantaloupe

Cucumis melo

Tender
Cantaloupe
Photo by Seth Vidal / CC BY-SA 2.0 / Wikimedia Commons

Northern Illinois: sow Jun.
Central Illinois: sow May–Jun.
Southern Illinois: sow May.

Ready in about 80 days from seed, 70 from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Carrots

Daucus carota

Cool seasonSuccession sow
Carrots
Photo by Evan-Amos / Public domain / Wikimedia Commons

Northern Illinois: sow Apr–Jul.
Central Illinois: sow Apr–Jul.
Southern Illinois: sow Mar–Jul.

Ready in about 70 days; sow again every 7 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Cauliflower

Brassica oleracea

Cool season
Cauliflower
Photo by Coyau / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: set out transplants Jul–Aug.
Central Illinois: set out transplants Apr–May, and again Jul.
Southern Illinois: set out transplants Jun–Jul.

Ready in about 95 days from seed, 68 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Cucumbers

Cucumis sativus

TenderSuccession sow
Cucumbers
Photo by Stephen Ausmus, USDA ARS / Public domain / Wikimedia Commons

Northern Illinois: sow May–Jun.
Central Illinois: sow May–Jun.
Southern Illinois: sow Apr–Jun.

Ready in about 58 days from seed, 50 from transplants; sow again every 7 weeks. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Eggplant

Solanum melongena

Tender
Eggplant
Photo by Billjones94 / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: set out transplants May–Jun.
Central Illinois: set out transplants May–Jun.
Southern Illinois: set out transplants Apr–Jun.

Ready in about 75 days from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Endive and escarole

Cichorium endivia

Cool seasonSuccession sow
Endive and escarole
Photo by Montréalais / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: sow Apr–May, and again Aug.
Central Illinois: sow Apr–May, and again Jul–Aug.
Southern Illinois: sow Mar–Apr, and again Jul–Aug.

Ready in about 90 days from seed, 70 from transplants; sow again every 8 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Garlic

Allium sativum

Cool seasonOverwinters
Garlic
Photo by Billjones94 / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: plant Sep.
Central Illinois: plant Oct.
Southern Illinois: plant Oct.

Ready in about 240 days.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Green beans

Phaseolus vulgaris

TenderSuccession sow
Green beans
Photo by Juan Carlos Fonseca Mata / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow May–Jun, and again May–Aug.
Central Illinois: sow May–Jun, and again May–Jul.
Southern Illinois: sow Apr–Jun, and again Jul.

Ready in about 55 days; sow again every 5 weeks. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Green onions

Allium fistulosum

Cool seasonSuccession sow
Green onions
Photo by Evan-Amos / Public domain / Wikimedia Commons

Northern Illinois: plant Apr–May.
Central Illinois: plant Mar–May.
Southern Illinois: plant Mar–Apr.

Ready in about 65 days from seed, 50 from transplants; sow again every 6 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Kale

Brassica oleracea

Cool season
Kale
Photo by Rasbak / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: set out transplants Apr–May, and again Aug.
Central Illinois: set out transplants Apr, and again Jul–Aug.
Southern Illinois: set out transplants Mar–Apr, and again Jul.

Ready in about 60 days from seed, 45 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Kohlrabi

Brassica oleracea

Cool season
Kohlrabi
Photo by Unknown author / CC0 / Wikimedia Commons

Northern Illinois: sow Apr, and again Jul.
Central Illinois: sow Mar–Apr, and again Jul.
Southern Illinois: sow Mar, and again Jun.

Ready in about 55 days from seed, 45 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Lettuce

Lactuca sativa

Cool seasonSuccession sow
Lettuce
Photo by Geo Lightspeed7 / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow Apr–May, and again Jul–Sep.
Central Illinois: sow Apr, and again Jul–Aug.
Southern Illinois: sow Mar–Apr, and again Jun–Aug.

Ready in about 65 days from seed, 50 from transplants; sow again every 6 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Mustard greens

Brassica juncea

Cool season
Mustard greens
Photo by Infrogmation of New Orleans / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow Apr–Jun, and again Jul–Sep.
Central Illinois: sow Apr, and again Jul–Aug.
Southern Illinois: sow Mar–Apr, and again Jun–Aug.

Ready in about 45 days.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Okra

Abelmoschus esculentus

Tender
Okra
Photo by Pedro Acevedo-Rodriguez / CC0 / Smithsonian Open Access / via USDA PLANTS

Northern Illinois: set out transplants May–Jun.
Central Illinois: set out transplants May–Jun.
Southern Illinois: set out transplants Apr–Jun.

Ready in about 55 days from seed, 45 from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Parsnips

Pastinaca sativa

Cool season
Parsnips
Photo by Jeffery Martin / CC0 / Wikimedia Commons

Northern Illinois: sow May–Aug.
Central Illinois: sow May–Jul.
Southern Illinois: sow Apr–Jul.

Ready in about 120 days.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Peas

Pisum sativum

Cool seasonSuccession sow
Peas
Photo by David Adam Kess / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow Apr–May.
Central Illinois: sow Mar–May.
Southern Illinois: sow Mar–Apr.

Ready in about 65 days; sow again every 5 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Peppers

Capsicum annuum

Tender
Peppers
Photo by Kham Tran - www.khamtran.com / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: set out transplants Jun–Jul.
Central Illinois: set out transplants May–Jul.
Southern Illinois: set out transplants May–Jun.

Ready in about 70 days from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Potatoes

Solanum tuberosum

Cool season
Potatoes
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Northern Illinois: plant Apr.
Central Illinois: plant Apr.
Southern Illinois: plant Mar.

Ready in about 100 days.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Pumpkins

Cucurbita pepo

Tender
Pumpkins
Photo by HalfGig / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: sow Jun.
Central Illinois: sow May–Jun.
Southern Illinois: sow May.

Ready in about 110 days from seed, 95 from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Radishes

Raphanus sativus

Cool seasonSuccession sow
Radishes
Photo by Rasbak / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: sow Apr–Jun, and again Aug–Sep.
Central Illinois: sow Apr–Jun, and again Aug.
Southern Illinois: sow Mar–May, and again Jul–Aug.

Ready in about 28 days; sow again every 3 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Rhubarb

Rheum rhabarbarum

Perennial
Rhubarb
Photo by DeFacto / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: plant Apr–May, and again Aug.
Central Illinois: plant Mar–May, and again Jul–Aug.
Southern Illinois: plant Mar–May, and again Jul.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Rutabagas

Brassica napus

Cool season
Rutabagas
Photo by Seedambassadors / CC BY-SA 3.0 / Wikimedia Commons

Northern Illinois: sow May–Aug.
Central Illinois: sow May–Jul.
Southern Illinois: sow Apr–Jul.

Ready in about 95 days.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Spinach

Spinacia oleracea

Cool seasonSuccession sow
Spinach
Photo by Victor M. Vicente Selvas / Public domain / Wikimedia Commons

Northern Illinois: sow Apr, and again Aug–Sep.
Central Illinois: sow Mar–Apr, and again Jul–Aug.
Southern Illinois: sow Mar–Apr, and again Jul–Aug.

Ready in about 42 days; sow again every 5 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Summer squash

Cucurbita pepo

TenderSuccession sow
Summer squash
Photo by INRA DIST from France / CC BY 2.0 / Wikimedia Commons

Northern Illinois: sow May–Jun.
Central Illinois: sow May–Jun.
Southern Illinois: sow Apr–Jun.

Ready in about 50 days from seed, 40 from transplants; sow again every 7 weeks. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Sweet corn

Zea mays

TenderSuccession sow
Sweet corn
Photo by Royalbroil / CC BY-SA 2.5 / Wikimedia Commons

Northern Illinois: sow May–Jul.
Central Illinois: sow May–Jul.
Southern Illinois: sow Apr–Jun.

Ready in about 78 days; sow again every 6 weeks. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Sweet potatoes

Ipomoea batatas

Tender
Sweet potatoes
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Northern Illinois: set out transplants May–Jun.
Central Illinois: set out transplants May–Jun.
Southern Illinois: set out transplants Apr–May.

Ready in about 100 days from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Swiss chard

Beta vulgaris

Cool season
Swiss chard
Photo by Neelix / Public domain / Wikimedia Commons

Northern Illinois: plant Apr–May, and again Jul–Aug.
Central Illinois: plant Apr–Jun, and again Jul–Aug.
Southern Illinois: plant Mar–May, and again Jul.

Ready in about 55 days from seed, 40 from transplants.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Tomatoes

Solanum lycopersicum

Tender
Tomatoes
Photo by Michal Klajban / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: set out transplants May–Jun.
Central Illinois: set out transplants May–Jun.
Southern Illinois: set out transplants Apr–May.

Ready in about 75 days from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Turnips

Brassica rapa

Cool seasonSuccession sow
Turnips
Photo by thebittenword.com / CC BY 2.0 / Wikimedia Commons

Northern Illinois: sow May–Aug.
Central Illinois: sow May–Jul, and again Jul–Aug.
Southern Illinois: sow Apr–Jul.

Ready in about 50 days; sow again every 5 weeks.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Watermelon

Citrullus lanatus

Tender
Watermelon
Photo by F ASTILY / CC BY-SA 4.0 / Wikimedia Commons

Northern Illinois: sow May–Jul.
Central Illinois: sow May–Jun.
Southern Illinois: sow Apr–Jun.

Ready in about 85 days from seed, 75 from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

Winter squash

Cucurbita moschata

Tender
Winter squash
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Northern Illinois: sow Jun.
Central Illinois: sow May–Jun.
Southern Illinois: sow May.

Ready in about 95 days from seed, 80 from transplants. Tender: in spring, from about April 25 in Chicago. If frost is in the forecast, hold off until it passes and nights stay above 36°F.

Source: University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign), When to Plant | Home Vegetable Gardening. Days to harvest: Ezina crop catalog, from state extension guides.

§ 040 · Questions

Questions about planting in Illinois

When is the last frost in Illinois?

On average from about April 10 in Chicago to April 30 in Schaumburg. Frost is over 9 years in 10 by May 8 to May 29.

When can I plant tomatoes in Illinois?

The extension service lists April to June. Tomatoes are frost-tender, so Ezina dates them from about April 25 in Chicago. If frost is in the forecast, wait until it passes.

What can I plant in Illinois in October?

The extension calendar lists garlic for October.

Is it too late for a fall garden?

The latest fall windows on the calendar close in October. Filter by Fall above to see what is still open.

Why not use my USDA zone?

A zone is the coldest winter night, not a frost date. These dates come from NOAA station records and the extension service.

Can Ezina date plantings for my address?

Yes. Run Ezina Dig on your address and your bed plans are dated from that site's own frost records, on iPhone and Android in the contiguous U.S.

Changes

29 Sept 2026: page published.

Sources

University of Illinois Extension (College of Agricultural, Consumer & Environmental Sciences, University of Illinois Urbana-Champaign): When to Plant | Home Vegetable Gardening.

NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, station freeze probabilities. U.S. Census Bureau, Vintage 2025 city and town population estimates and 2020 place gazetteer. Days to harvest and re-sowing intervals: Ezina's crop catalog, compiled from state Cooperative Extension guides. Photos: Wikimedia Commons and USDA PLANTS, credited under each photo. Checked Sept 2026.