When to Plant in Illinois: Vegetable & Flower Planting Calendar
Quick answer
Plant around your local last spring frost: across the 1396 Illinois ZIP codes where frost comes in most years, the median is Apr 17 and the median first fall frost is Oct 21 (nearest NOAA station, 1991–2020). Transplant tomatoes 1–2 weeks after your last frost: Zone 5 areas: May 1 – May 8; Zone 6 areas: Apr 22 – Apr 29; Zone 7 areas: Apr 15 – Apr 22.
Illinois spans USDA hardiness zones 5a–7a on the 2023 USDA map (by ZIP code, via PRISM). For the 1396 of its 1396 ZIP codes where frost comes in most years, the nearest NOAA station’s median last spring frost (32°F, 1991–2020) is Apr 17 (middle 80% of ZIP codes: Apr 7 – Apr 26) and the median first fall frost is Oct 21 (Oct 14 – Oct 29). Use this guide to time seed-starting, transplanting and fall planting.
Where these dates come from: every date range is counted from the median (50% probability) 32°F last spring and first fall frost dates in NOAA’s 1991–2020 U.S. Climate Normals for the area shown. The rule under each date, such as “4–6 weeks before last frost,” shows how it was counted. These are averages: in about half of years a frost still comes after the spring date, and elevation, nearby water and microclimate can shift your yard by a week or more. For dates for your exact location, enter your ZIP code in the planner.
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
Illinois frost dates by zone area
| Zone areas | Most common nearest NOAA stations | Median last spring frost (32°F) | Median first fall frost (32°F) |
|---|---|---|---|
| Zone 5 (435 ZIP codes) | Rockford Gtr Rockford Airport, IL, Aurora, IL, Peru, IL | Apr 24middle 80%: Apr 19 – Apr 29 | Oct 17middle 80%: Oct 12 – Oct 24 |
| Zone 6 (790 ZIP codes) | Chicago Northerly Is, IL, Chicago Ohare Intl Airport, IL, Park Forest, IL | Apr 15middle 80%: Apr 7 – Apr 23 | Oct 22middle 80%: Oct 17 – Oct 31 |
| Zone 7 (157 ZIP codes) | Cahokia St Louis Airport, IL, Alton - Melvin Price L&D, IL, Sparta 1 W, IL | Apr 8middle 80%: Apr 3 – Apr 14 | Oct 26middle 80%: Oct 20 – Nov 5 |
Source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991–2020, annual/seasonal freeze-date probabilities (32°F, 50% probability). Station-level medians; your yard may differ.
How this table is built: each Illinois ZIP code is matched to its nearest NOAA 1991–2020 freeze-data station (within 60 miles) and grouped by its 2023 USDA hardiness zone; dates are medians across the ZIP codes in each group. Some nearest stations are across the state line (Beloit, WI, Boswell 4Wnw, IN, Brodhead Wwtp, WI, Burlington 2S, IA, Canton L&D 20, MO, Cape Girardeau Muni Airport, MO…). For your own ZIP, use the planner.
Illinois vegetable planting calendar
Planting dates for each zone area of Illinois, counted from that area’s median frost dates (shown under each column). Rows run in calendar order. For your exact dates, enter your ZIP.
| Plant, task and rule | Zone 5 areasLast frost Apr 24 · First frost Oct 17 | Zone 6 areasLast frost Apr 15 · First frost Oct 22 | Zone 7 areasLast frost Apr 8 · First frost Oct 26 |
|---|---|---|---|
| Broccoli · Start indoors8–10 weeks before last frost | Feb 13 – Feb 27 | Feb 4 – Feb 18 | Jan 28 – Feb 11 |
| Cabbage · Start indoors8–10 weeks before last frost | Feb 13 – Feb 27 | Feb 4 – Feb 18 | Jan 28 – Feb 11 |
| Kale · Start indoors8–10 weeks before last frost | Feb 13 – Feb 27 | Feb 4 – Feb 18 | Jan 28 – Feb 11 |
| Tomatoes · Start indoors6–8 weeks before last frost | Feb 27 – Mar 13 | Feb 18 – Mar 4 | Feb 11 – Feb 25 |
| Peppers · Start indoors6–8 weeks before last frost | Feb 27 – Mar 13 | Feb 18 – Mar 4 | Feb 11 – Feb 25 |
| Eggplant · Start indoors6–8 weeks before last frost | Feb 27 – Mar 13 | Feb 18 – Mar 4 | Feb 11 – Feb 25 |
| Peas · Direct sow4–6 weeks before last frost | Mar 13 – Mar 27Harvest (est.) May 12 – Jun 15 | Mar 4 – Mar 18Harvest (est.) May 3 – Jun 6 | Feb 25 – Mar 11Harvest (est.) Apr 26 – May 30 |
| Spinach · Direct sow4–6 weeks before last frost | Mar 13 – Mar 27Harvest (est.) Apr 27 – May 26 | Mar 4 – Mar 18Harvest (est.) Apr 18 – May 17 | Feb 25 – Mar 11Harvest (est.) Apr 11 – May 10 |
| Basil · Start indoors4–6 weeks before last frost | Mar 13 – Mar 27 | Mar 4 – Mar 18 | Feb 25 – Mar 11 |
| Radishes · Direct sow2–5 weeks before last frost | Mar 20 – Apr 10Harvest (est.) Apr 9 – May 10 | Mar 11 – Apr 1Harvest (est.) Mar 31 – May 1 | Mar 4 – Mar 25Harvest (est.) Mar 24 – Apr 24 |
| Lettuce · Direct sow2–4 weeks before last frost | Mar 27 – Apr 10Harvest (est.) May 26 – Jun 29 | Mar 18 – Apr 1Harvest (est.) May 17 – Jun 20 | Mar 11 – Mar 25Harvest (est.) May 10 – Jun 13 |
| Onions (sets/transplants) · Plant sets/transplants2–4 weeks before last frost | Mar 27 – Apr 10Harvest (est.) Jun 20 – Aug 8 | Mar 18 – Apr 1Harvest (est.) Jun 11 – Jul 30 | Mar 11 – Mar 25Harvest (est.) Jun 4 – Jul 23 |
| Broccoli · Transplant2–4 weeks before last frost | Mar 27 – Apr 10Harvest (est.) May 16 – Jun 19 | Mar 18 – Apr 1Harvest (est.) May 7 – Jun 10 | Mar 11 – Mar 25Harvest (est.) Apr 30 – Jun 3 |
| Cabbage · Transplant2–4 weeks before last frost | Mar 27 – Apr 10Harvest (est.) Jun 5 – Jul 9 | Mar 18 – Apr 1Harvest (est.) May 27 – Jun 30 | Mar 11 – Mar 25Harvest (est.) May 20 – Jun 23 |
| Kale · Transplant2–4 weeks before last frost | Mar 27 – Apr 10 | Mar 18 – Apr 1 | Mar 11 – Mar 25 |
| Marigolds · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 3 – Apr 24 | Mar 25 – Apr 15 | Mar 18 – Apr 8 |
| Zinnias · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 3 – Apr 24 | Mar 25 – Apr 15 | Mar 18 – Apr 8 |
| Potatoes · Plant seed potatoes1–2 weeks before last frost | Apr 10 – Apr 17Harvest (est.) Jul 4 – Aug 5 | Apr 1 – Apr 8Harvest (est.) Jun 25 – Jul 27 | Mar 25 – Apr 1Harvest (est.) Jun 18 – Jul 20 |
| Marigolds · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | Apr 24 – May 8 | Apr 15 – Apr 29 | Apr 8 – Apr 22 |
| Zinnias · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | Apr 24 – May 8 | Apr 15 – Apr 29 | Apr 8 – Apr 22 |
| Tomatoes · Transplant1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jul 10 – Aug 6 | Apr 22 – Apr 29Harvest (est.) Jul 1 – Jul 28 | Apr 15 – Apr 22Harvest (est.) Jun 24 – Jul 21 |
| Beans (bush & pole) · Direct sow1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jun 15 – Jul 17 | Apr 22 – Apr 29Harvest (est.) Jun 6 – Jul 8 | Apr 15 – Apr 22Harvest (est.) May 30 – Jul 1 |
| Sweet corn · Direct sow1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jul 5 – Aug 6 | Apr 22 – Apr 29Harvest (est.) Jun 26 – Jul 28 | Apr 15 – Apr 22Harvest (est.) Jun 19 – Jul 21 |
| Cucumbers · Direct sow1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jun 10 – Jul 12 | Apr 22 – Apr 29Harvest (est.) Jun 1 – Jul 3 | Apr 15 – Apr 22Harvest (est.) May 25 – Jun 26 |
| Squash · Direct sow1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jun 10 – Jun 27 | Apr 22 – Apr 29Harvest (est.) Jun 1 – Jun 18 | Apr 15 – Apr 22Harvest (est.) May 25 – Jun 11 |
| Pumpkins · Direct sow1–3 weeks after last frost | May 1 – May 15Harvest (est.) Jul 20 – Aug 23 | Apr 22 – May 6Harvest (est.) Jul 11 – Aug 14 | Apr 15 – Apr 29Harvest (est.) Jul 4 – Aug 7 |
| Basil · Transplant1–2 weeks after last frost | May 1 – May 8Harvest (est.) Jun 12 – Jun 19 | Apr 22 – Apr 29Harvest (est.) Jun 3 – Jun 10 | Apr 15 – Apr 22Harvest (est.) May 27 – Jun 3 |
| Peppers · Transplant2–3 weeks after last frost | May 8 – May 15Harvest (est.) Jul 12 – Jul 29 | Apr 29 – May 6Harvest (est.) Jul 3 – Jul 20 | Apr 22 – Apr 29Harvest (est.) Jun 26 – Jul 13 |
| Eggplant · Transplant2–3 weeks after last frost | May 8 – May 15Harvest (est.) Jul 17 – Aug 13 | Apr 29 – May 6Harvest (est.) Jul 8 – Aug 4 | Apr 22 – Apr 29Harvest (est.) Jul 1 – Jul 28 |
| Broccoli · Fall transplant10–12 weeks before first fall frost | Jul 25 – Aug 8Harvest (est.) Sep 13 – Oct 17 | Jul 30 – Aug 13Harvest (est.) Sep 18 – Oct 22 | Aug 3 – Aug 17Harvest (est.) Sep 22 – Oct 26 |
| Cabbage · Fall transplant10–12 weeks before first fall frost | Jul 25 – Aug 8Harvest (est.) Oct 3 – Nov 6 | Jul 30 – Aug 13Harvest (est.) Oct 8 – Nov 11 | Aug 3 – Aug 17Harvest (est.) Oct 12 – Nov 15 |
| Kale · Fall sow8–10 weeks before first fall frost | Aug 8 – Aug 22Harvest (est.) Sep 27 – Oct 31 | Aug 13 – Aug 27Harvest (est.) Oct 2 – Nov 5 | Aug 17 – Aug 31Harvest (est.) Oct 6 – Nov 9 |
| Lettuce · Fall sow6–8 weeks before first fall frost | Aug 22 – Sep 5Harvest (est.) Oct 21 – Nov 24 | Aug 27 – Sep 10Harvest (est.) Oct 26 – Nov 29 | Aug 31 – Sep 14Harvest (est.) Oct 30 – Dec 3 |
| Spinach · Fall sow4–7 weeks before first fall frost (Virginia Tech) | Aug 29 – Sep 19Harvest (est.) Oct 13 – Nov 18 | Sep 3 – Sep 24Harvest (est.) Oct 18 – Nov 23 | Sep 7 – Sep 28Harvest (est.) Oct 22 – Nov 27 |
| Radishes · Fall sow4–6 weeks before first fall frost | Sep 5 – Sep 19Harvest (est.) Sep 25 – Oct 19 | Sep 10 – Sep 24Harvest (est.) Sep 30 – Oct 24 | Sep 14 – Sep 28Harvest (est.) Oct 4 – Oct 28 |
| Daffodils · Fall plant bulbs4 weeks before to 2 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Sep 19 – Oct 31 | Sep 24 – Nov 5 | Sep 28 – Nov 9 |
| Tulips · Fall plant bulbs2 weeks before to 4 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Oct 3 – Nov 14 | Oct 8 – Nov 19 | Oct 12 – Nov 23 |
| Garlic · Fall plant cloves2 weeks before to 3 weeks after first fall frost, while the soil is still workable (SDSU, Illinois, Virginia Tech) | Oct 3 – Nov 7Harvest (est.) Jun 10, 2027 – Aug 4, 2027 | Oct 8 – Nov 12Harvest (est.) Jun 15, 2027 – Aug 9, 2027 | Oct 12 – Nov 16Harvest (est.) Jun 19, 2027 – Aug 13, 2027 |
About the harvest estimates
Each expected harvest window adds the days to harvest from the sources below to the planting window. Days count from sowing seed (or planting seed potatoes, onion sets or garlic cloves) or, where marked, from setting transplants out; “Start indoors” rows have no harvest of their own. Harvest timing varies with variety and weather, and many crops keep producing for weeks after the first picking. For frost-tender crops (tomatoes, peppers, eggplant, beans, sweet corn, cucumbers, squash, pumpkins, basil) the window stops at the first fall frost: harvest may end early at the first fall frost. Flowers and bulbs show no harvest window, and kale has no sourced figure for spring transplants.
Sources: UF/IFAS Extension, Florida Vegetable Gardening Guide (SP103/VH021), Table 1, “Days to Harvest”; University of Maryland Extension, Growing Onions in a Home Garden; University of Maryland Extension, Growing Garlic in a Home Garden; University of Maryland Extension, Growing Basil in a Home Garden.
Growing notes for each crop
- Peas: Tolerates light frost; sow when soil is workable
- Spinach: Fall crop too: sow 4–7 weeks before first fall frost (Virginia Tech)
- Lettuce: Bolts in heat; succession sow; fall crop too
- Radishes: Fast (3–4 weeks); sow again for fall (see Fall sow dates)
- Kale: Fall crop too (see Fall sow dates); frost sweetens leaves
- Onions (sets/transplants): Choose day-length type suited to your latitude
- Potatoes: Soil at least 45°F (UMD); hill as plants grow
- Broccoli: Cool-season; harden off; good fall crop
- Cabbage: Cool-season; harden off; good fall crop
- Tomatoes: Wait for nights reliably above about 52°F (Colorado State)
- Peppers: Need warm soil: about 65°F is optimal for transplanting (UC ANR)
- Eggplant: Transplant after nights stay above 50°F (UMN)
- Beans (bush & pole): Seeds rot in cold, wet soil
- Sweet corn: Soil 60°F+ (UNH, UMN); plant in blocks for pollination
- Cucumbers: Frost-tender; watch for cucumber beetles
- Squash: Frost-tender; watch for squash vine borer
- Pumpkins: For October pumpkins, many sow in late May–June
- Basil: Very cold-sensitive
- Marigolds: Easy warm-season annual
- Zinnias: Easy warm-season annual
- Tulips: Our frost-date window is an approximation of that soil rule. In zone 9, chill bulbs 12–16 weeks first (Clemson)
- Daffodils: Our frost-date window is an approximation of that soil rule; slightly earlier than tulips is fine
- Garlic: Harvest the following early summer
Illinois USDA zone guides: Zone 5 planting guide Zone 6 planting guide Zone 7 planting guide
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
Tips for Illinois gardeners
- Watch soil temperature, not just the calendar — warm-season crops stall in cold soil. An inexpensive soil thermometer helps.
- Harden off transplants over 7–10 days before planting out (UC ANR, SDSU).
- Ask your local Cooperative Extension office about varieties and timing for your county; find it in the USDA NIFA land-grant university directory.
- Keep weeds down early — see our weed identification guide.
Frequently asked questions
When is the last frost in Illinois?
Across the 1396 Illinois ZIP codes where frost comes in most years, the median last spring frost (32°F, NOAA 1991–2020) at the nearest station is Apr 17, and the middle 80% of ZIP codes range from Apr 7 to Apr 26. Check the average for your ZIP code, and remember frost can occur after the average date.
When can I plant tomatoes in Illinois?
Transplant tomatoes outdoors 1–2 weeks after your average last frost, once nights stay above about 52°F (Colorado State). Typical dates: Zone 5 areas: May 1 – May 8; Zone 6 areas: Apr 22 – Apr 29; Zone 7 areas: Apr 15 – Apr 22.
What USDA zone is Illinois?
Illinois spans roughly USDA hardiness zones 5a–7a on the 2023 USDA map (by ZIP code, via PRISM). Hardiness zones describe winter low temperatures, not frost dates.
Other state planting calendars
Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware District of Columbia Florida Georgia Hawaii Idaho Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming All states