Joliet, Illinois planting calendar and frost dates
Joliet is in USDA hardiness zone 6a. The last spring frost typically comes around April 19 and the first fall frost around October 25, giving about 188 frost-free days a year.
- Typical last frost
- April 19
- Typical first frost
- October 25
- Frost-free season
- 188 days
Frost dates in Joliet
Last spring frost
- April 3Risky: frost later than this in 9 years out of 10
- April 19Typical: a later frost in half of years
- May 7Safe: a later frost only 1 year in 10
First fall frost
- October 12Risky: frost earlier than this 1 year in 10
- October 25Typical: an earlier frost in half of years
- November 6Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 188 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around April 5 and returns around November 4.
NOAA U.S. Climate Normals 1991-2020 for Joliet Brandon Rd Dam, 1.9 miles SW of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.
What to plant each month in Joliet
January
Start indoors: collard greens, leeks, onions, petunias, ranunculus
February
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, ginger, kale, leeks, lettuce, marigolds, onions, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons
March
Start indoors: basil, black-eyed susans, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, lettuce, marigolds, nasturtiums, peppers, ranunculus, sage, snapdragons, spinach, swiss chard, tomatoes
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, swiss chard, thyme, turnips
May
Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, ginger, grapes, green beans, green onions, kentucky bluegrass, lavenders, lilies, marigolds, mints, nasturtiums, okra, oregano, parsley, peanuts, peppers, perennial ryegrass, petunias, pumpkins, rosemary, sage, st. augustinegrass, sunflowers, sweet corn, sweet peas, sweet potatoes, tall fescue, thyme, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
June
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, sweet potatoes, zinnias, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
Plant for fall: brussels sprouts, collard greens, lettuce, swiss chard
August
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, spinach, tall fescue, tulips, turnips
October
Plant for fall: crocuses, daffodils, daylilies, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
November
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
December
Start indoors: onions
Frost dates and zones by ZIP code in Joliet
All 8 of Joliet's main ZIP codes take their frost dates from Joliet Brandon Rd Dam, so the dates on this page apply across the city. The hardiness zone is 5b in 60431, 60447, 60586, and 6a in 60421, 60432, 60433, 60435, 60436.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 60421 | 6a | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60431 | 5b | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60432 | 6a | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60433 | 6a | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60435 | 6a | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60436 | 6a | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60447 | 5b | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
| 60586 | 5b | Joliet Brandon Rd Dam, 1.9 mi SW | Apr 19 | Oct 25 |
Joliet Brandon Rd Dam also supplies the frost dates for Plainfield, so their planting calendars match Joliet's.
Planting dates for popular crops in Joliet
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 21 to Apr 4 | May 16 to 30 | — |
| Strawberries | — | Mar 8 to 22 | — |
| Lettuce | Feb 22 to Mar 8 | Apr 12 to 26 | Jul 26 to Aug 30 |
| Cilantro | Mar 8 to 22 | Apr 19 to 26 | — |
| Basil | Mar 28 to Apr 11 | May 16 to 23 | — |
| Potatoes | — | Apr 18 to 25 | — |
| Garlic | — | Mar 8 to 22 | Oct 25 to Nov 8 |
| Onions | Dec 28 to Feb 8 | Mar 22 to Apr 5 | — |
| Cucumbers | Apr 18 to May 2 | May 16 to 30 | — |
| Pumpkins | Apr 18 to May 2 | May 16 to 30 | — |
| Peppers | Feb 28 to Mar 28 | May 16 to 30 | — |
| Carrots | — | Mar 29 to Apr 19 | Aug 2 to 23 |
| Sweet Potatoes | — | May 30 to Jun 6 | — |
| Watermelons | Apr 11 to 25 | May 16 to 30 | — |
| Sweet Corn | — | Apr 19 to May 3 | — |
| Green Beans | — | May 16 to 30 | — |
| Zucchini | Apr 18 to May 2 | May 16 to 30 | — |
| Broccoli | Feb 1 to 22 | Mar 22 to Apr 5 | Aug 9 to Sep 6 |
| Peas | — | Mar 8 to 22 | Aug 2 to 16 |
| Spinach | Mar 8 to 15 | Apr 12 to 26 | Aug 16 to Sep 20 |
| Sunflowers | — | Apr 19 to May 10 | — |
| Zinnias | May 18 to 25 | Jun 15 to 29 | — |
| Tulips | — | — | Sep 13 to Nov 8 |
| Daffodils | — | — | Sep 13 to Oct 25 |
| Grass Seed | — | Mar 8 to 22 | Sep 13 to 27 |
Nearby cities
- Plainfield, IL zone 5b, last frost Apr 19
- Bolingbrook, IL zone 6a, last frost Apr 19
- Naperville, IL zone 5b, last frost Apr 19
- Orland Park, IL zone 6a, last frost Apr 10
- Tinley Park, IL zone 6a, last frost Apr 23
- Aurora, IL zone 5b, last frost Apr 19
Planting in IllinoisAbout zone 6aPrintable calendar for Joliet
Questions
When is the last frost in Joliet?
Around April 19 in a typical year, based on NOAA's 1991-2020 records for Joliet Brandon Rd Dam. There is still a 1 in 10 chance of frost after May 7.
What planting zone is Joliet in?
USDA hardiness zone 6a (2023 map), with parts of the city in zone 5b. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Joliet?
Start seeds indoors March 21 to April 4 and set plants out May 16 to 30.
When is the first frost in Joliet?
Around October 25 in a typical year, and before October 12 about 1 year in 10.