Frost Dates for Wilmington, IL 60481
Last spring frost April 29 · First fall frost October 9 · 163 frost-free days · USDA Zone 5b
ZIP 60481 has about 11,200 people.
Moderate season: 163 frost-free days. Spring frost risk spans April 13–May 16 (33 days). Fall frost risk spans September 28–October 20 (22 days).
Frost probability for 60481
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 16 | April 29 | April 13 |
| Fall (first frost) | September 28 | October 9 | October 20 |
Dates come from NOAA 1971–2000 freeze probabilities at AURORA (56.7 km away); the 50% date is the median year.
Which crops fit a 163-day season in Wilmington
In Wilmington (163 frost-free days, a moderate season), 31 of 56 planner crops fit outright, 24 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 25 | May 13–May 20 | 121 | fits: 80 days to maturity, 121 available after May 13. | Jun 9 |
| Pepper | Mar 18 | May 13–May 20 | 121 | fits: 75 days to maturity, 121 available after May 13. | Jun 14 |
| Lettuce | Mar 4 | Apr 1–Apr 8 | 198 | two-plantings: Plant Apr 1 and again by Aug 18; both mature before Oct 16. | Aug 18 |
| Carrots | — | Apr 8–Apr 15 | 205 | fits: 70 days to maturity, 205 available after Apr 8. | Aug 7 |
| Cucumber | Apr 8 | May 13–May 20 | 135 | two-plantings: Plant May 13 and again by Jul 13; both mature before Sep 25. | Jul 13 |
| Beans | — | May 6–May 20 | 149 | two-plantings: Plant May 6 and again by Jul 20; both mature before Oct 2. | Jul 20 |
| Peas | — | Mar 4–May 13 | 226 | fits: 65 days to maturity, 226 available after Mar 4. | Jul 29 |
| Zucchini | Apr 15 | May 13–May 20 | 135 | two-plantings: Plant May 13 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Onion | Feb 4 | Apr 1–Apr 15 | 198 | fits: 100 days to maturity, 198 available after Apr 1. | — |
| Spinach | — | Mar 4–Apr 22 | 240 | two-plantings: Plant Mar 4 and again by Sep 6; both mature before Oct 30. | Sep 6 |
| Kale | Feb 18 | Apr 1–Apr 15 | 212 | two-plantings: Plant Apr 1 and again by Aug 22; both mature before Oct 30. | Aug 22 |
| Broccoli | Mar 4 | Apr 1–Apr 15 | 198 | fits: 80 days to maturity, 198 available after Apr 1. | Jul 14 |
| Cabbage | Mar 4 | Apr 1–Apr 15 | 212 | fits: 70 days to maturity, 212 available after Apr 1. | Aug 7 |
| Radish | — | Mar 4–May 27 | 226 | two-plantings: Plant Mar 4 and again by Sep 7; both mature before Oct 16. | Sep 7 |
| Beets | — | Mar 4–May 27 | 226 | two-plantings: Plant Mar 4 and again by Aug 8; both mature before Oct 16. | Aug 8 |
| Potatoes | — | Apr 15–Apr 22 | 184 | fits: 90 days to maturity, 184 available after Apr 15. | — |
| Garlic | — | Oct 9 | 268 | overwinter: Plant Oct 9 to Oct 30; harvest the following summer. | Oct 30 |
| Strawberry | — | Mar 25–May 20 | 219 | perennial: A perennial: plant Mar 25; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 1 | May 6–May 13 | 135 | fits: 75 days to maturity, 135 available after May 6. | Jun 21 |
| Pumpkin | Apr 15 | May 13–May 13 | 128 | fits: 100 days to maturity, 128 available after May 13. | May 27 |
| Cauliflower | Mar 18 | Apr 22–May 6 | 177 | fits: 75 days to maturity, 177 available after Apr 22. | Jul 19 |
| Swiss Chard | Mar 4 | Apr 15–Apr 15 | 184 | two-plantings: Plant Apr 15 and again by Aug 8; both mature before Oct 16. | Aug 8 |
| Arugula | — | Mar 4–May 27 | 240 | two-plantings: Plant Mar 4 and again by Sep 6; both mature before Oct 30. | Sep 6 |
| Brussel Sprouts | Mar 4 | Apr 1–Apr 15 | 212 | fits: 100 days to maturity, 212 available after Apr 1. | Jul 8 |
| Butternut Squash | Apr 15 | May 13–May 20 | 128 | fits: 100 days to maturity, 128 available after May 13. | May 27 |
| Eggplant | Mar 11 | May 13–May 20 | 121 | fits: 70 days to maturity, 121 available after May 13. | Jun 19 |
| Okra | Apr 1 | May 6–May 13 | 142 | two-plantings: Plant May 6 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Basil | Mar 25 | May 20–May 20 | 128 | fits: 60 days to maturity, 128 available after May 20. | Jul 13 |
| Cilantro | — | Apr 1–Apr 22 | 198 | two-plantings: Plant Apr 1 and again by Aug 13; both mature before Oct 16. | Aug 13 |
| Parsley | Feb 18 | May 6–May 13 | 163 | fits: 70 days to maturity, 163 available after May 6. | Jul 24 |
| Celery | Feb 18 | May 6–May 20 | 163 | fits: 120 days to maturity, 163 available after May 6. | Jun 4 |
| Scallions | Feb 18 | Apr 1–Apr 15 | 212 | two-plantings: Plant Apr 1 and again by Aug 17; both mature before Oct 30. | Aug 17 |
| Turnip | — | Apr 1–Apr 15 | 212 | two-plantings: Plant Apr 1 and again by Aug 27; both mature before Oct 30. | Aug 27 |
| Kohlrabi | — | Mar 18–Apr 1 | 226 | two-plantings: Plant Mar 18 and again by Aug 22; both mature before Oct 30. | Aug 22 |
| Bok Choy | Apr 1 | Apr 22–Apr 29 | 177 | two-plantings: Plant Apr 22 and again by Aug 18; both mature before Oct 16. | Aug 18 |
| Collards | Feb 18 | Apr 1–Apr 15 | 212 | two-plantings: Plant Apr 1 and again by Aug 17; both mature before Oct 30. | Aug 17 |
| Cantaloupe | Apr 15 | May 13–May 20 | 121 | fits: 85 days to maturity, 121 available after May 13. | Jun 4 |
| Chives | Feb 4 | May 6–May 13 | 177 | fits: 90 days to maturity, 177 available after May 6. | — |
| Dill | — | Mar 4–May 27 | 226 | two-plantings: Plant Mar 4 and again by Aug 8; both mature before Oct 16. | Aug 8 |
| Oregano | Feb 18 | May 6–May 13 | 177 | fits: 80 days to maturity, 177 available after May 6. | — |
| Rosemary | Feb 4 | May 6–May 13 | 163 | fits: 80 days to maturity, 163 available after May 6. | — |
| Sage | Mar 4 | May 6–May 13 | 177 | fits: 75 days to maturity, 177 available after May 6. | — |
| Thyme | Feb 18 | May 6–May 13 | 177 | fits: 90 days to maturity, 177 available after May 6. | — |
| Calendula | Mar 18 | Apr 15–Apr 29 | 184 | two-plantings: Plant Apr 15 and again by Aug 13; both mature before Oct 16. | Aug 13 |
| Cosmos | Apr 1 | Apr 29–May 13 | 149 | two-plantings: Plant Apr 29 and again by Jul 13; both mature before Sep 25. | Jul 13 |
| Lavender | Feb 4 | Apr 29–May 13 | 184 | fits: 90 days to maturity, 184 available after Apr 29. | — |
| Marigolds | Mar 18 | Apr 29–May 6 | 149 | two-plantings: Plant Apr 29 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Melons | Apr 15 | May 13–May 20 | 121 | fits: 85 days to maturity, 121 available after May 13. | Jun 4 |
| Mint | — | Apr 29–May 13 | 184 | fits: 90 days to maturity, 184 available after Apr 29. | — |
| Nasturtiums | Apr 1 | Apr 29–May 6 | 149 | two-plantings: Plant Apr 29 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Pole Beans | — | May 6–May 20 | 142 | fits: 65 days to maturity, 142 available after May 6. | Jul 8 |
| Spaghetti Squash | Apr 15 | May 13–May 20 | 128 | fits: 90 days to maturity, 128 available after May 13. | Jun 6 |
| Sunflowers | — | Apr 29–May 13 | 149 | fits: 70 days to maturity, 149 available after Apr 29. | Jul 3 |
| Tomatillos | Mar 4 | May 6–May 13 | 128 | fits: 75 days to maturity, 128 available after May 6. | Jun 14 |
| Watermelon | Apr 15 | May 6–May 13 | 128 | fits: 80 days to maturity, 128 available after May 6. | Jun 9 |
| Yellow Squash | Apr 15 | May 13–May 20 | 135 | two-plantings: Plant May 13 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Zinnias | Apr 1 | Apr 29–May 13 | 149 | two-plantings: Plant Apr 29 and again by Jul 13; both mature before Sep 25. | Jul 13 |
Month by month in Wilmington
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 4), Lavender (Feb 4), Onion (Feb 4), Rosemary (Feb 4), Celery (Feb 18), Collards (Feb 18), +5 more. |
| March | Start indoors: Broccoli (Mar 4), Brussel Sprouts (Mar 4), Cabbage (Mar 4), Lettuce (Mar 4), Sage (Mar 4), Swiss Chard (Mar 4), +8 more. Direct sow from: Arugula (Mar 4), Beets (Mar 4), Dill (Mar 4), Peas (Mar 4), Radish (Mar 4), Spinach (Mar 4), +1 more. Plant: Strawberry (Mar 25). |
| April | Start indoors: Bok Choy (Apr 1), Corn (Apr 1), Cosmos (Apr 1), Nasturtiums (Apr 1), Okra (Apr 1), Zinnias (Apr 1), +9 more. Direct sow from: Cilantro (Apr 1), Turnip (Apr 1), Carrots (Apr 8), Potatoes (Apr 15), Sunflowers (Apr 29). Transplant from: Broccoli (Apr 1), Brussel Sprouts (Apr 1), Cabbage (Apr 1), Collards (Apr 1), Kale (Apr 1), Lettuce (Apr 1), +12 more. Last frost around April 29. |
| May | Direct sow from: Beans (May 6), Pole Beans (May 6). Transplant from: Celery (May 6), Chives (May 6), Corn (May 6), Okra (May 6), Oregano (May 6), Parsley (May 6), +17 more. Last sowing dates: Butternut Squash (May 27), Pumpkin (May 27). |
| June | Last sowing dates: Cantaloupe (Jun 4), Celery (Jun 4), Melons (Jun 4), Spaghetti Squash (Jun 6), Tomato (Jun 9), Watermelon (Jun 9), +4 more. |
| July | Last sowing dates: Sunflowers (Jul 3), Brussel Sprouts (Jul 8), Pole Beans (Jul 8), Basil (Jul 13), Cosmos (Jul 13), Cucumber (Jul 13), +11 more. |
| August | Last sowing dates: Cabbage (Aug 7), Carrots (Aug 7), Beets (Aug 8), Dill (Aug 8), Swiss Chard (Aug 8), Calendula (Aug 13), +8 more. |
| September | Last sowing dates: Arugula (Sep 6), Spinach (Sep 6), Radish (Sep 7). |
| October | Direct sow from: Garlic (Oct 9). First frost around October 9. Last sowing dates: Garlic (Oct 30). |
| November | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Wilmington, IL (ZIP 60481)?
The median last spring frost date for Wilmington, IL (ZIP code 60481) is around April 29. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before April 13; one in ten it runs past May 16.
What is the first fall frost date in Wilmington, IL?
The median first fall frost date for Wilmington, IL is around October 9. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around September 28 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Wilmington, IL?
The frost-free growing season in Wilmington is about 163 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Wilmington (163 frost-free days, a moderate season), 31 of 56 planner crops fit outright, 24 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Wilmington, IL?
Wilmington, IL is in USDA hardiness zone 5b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Wilmington, IL?
Start tomatoes indoors Mar 25 and plant out May 13 in Wilmington. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Wilmington?
Two: plant Apr 1 and again by Aug 18; both mature before Oct 16.
When do I plant garlic in Wilmington?
Oct 9 to Oct 30; it overwinters and is ready the following summer.
Which nearby ZIP has a longer season?
Manhattan (ZIP 60442) has 171 frost-free days, 8 more than Wilmington (ZIP 60481). See Manhattan ZIP 60442 frost dates
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