Do you know when to plant in Illinois? (2024)

Originally published by Kelly Allsup, February 2, 2021.

Believe it or not, it's never too early to start making plans for this year's garden. Knowing when to plant for your area and getting your plants started right will help you maximize the growing season.

When to grow?

Planting dates are determined two things: the first and last frost dates where you grow, and how much time it takes for a crop to mature. Always check the plant tag or seed packet for the recommended date.

Cool-Season Vegetables:These crops grow and develop best in the temperatures of early spring or fall. Some of these cool-season crops can withstand a frost without being damaged, and some are even improved by experiencing a light frost. Examples: carrots, kale, turnips, and radishes.
Warm-Season Vegetables: These crops do not grow well in lower temperatures and must be planted well after the average last frost date. Examples: tomatoes, squash, and peppers.

What planting zone do you live in?

The U.S. Department of Agriculture provides a nationalHardiness Zone mapwith 13 zones to help gardeners and growers pick the best plants for where they live. From top to tip, Illinois is almost 400 miles long and has five hardiness zones: 5a, 5b, 6a, 6b, and 7a.

Northern Illinois is covered by Zone 5a in the furthest northwestern counties, while the rest is zone 5b.
- Frost-free date: May 1-10. First frost: September 21-30.
Central Illinoisspans zones 5b and 6a.
- Frost-free date: April 11-30. First frost: October 11-20.
Southern Illinois includes zone 6a, 6b and 7a.
- Frost-free date April 1-10. First frost: October 21-30.

The frost dates are averages, but the Illinois State Water Survey has a map of the latest spring frost dates that is also a good guide to be aware of. Forexample,McLean County has gotten frost as late as May 28.

Southern Illinois’ longer growing season means gardeners there can start their crops about 2 weeks earlier than Central Illinois. They also can typically harvest for about two weeks longer. On the other hand, Northern Illinois has a shorter growing season and should plant 2 weeks later than I do.

Illinois Fruit and Vegetable Planting Dates

The below chart covers suggested date ranges to plant vegetable seeds or transplants outside in Northern, Central and Southern Illinois. Always confirm plant dates with the seed packet or plant tag. When there are two dates, the crop can be planted and harvested twice for both a summer and fall crop.

Need a hand?

Check out these blogs for tips on seed starting and how to grow specific vegetables.

Starting Seeds:Starting Seeds in Spring, Easy DIY Seeding with Limited Materials, Hardening Off Indoor Seedlings
Varieties:Cool-Season Vegetables,Warm Season Vegetables,Asparagus,Carrots,Sweet Potatoes,Lettuce,Tomatoes,Different Types of Tomatoes,Cucurbits,Different Types of Cucurbits,Peppers,Sweet Corn.

Contact us! And don't forget, if you have questions you can always reach out to horticulture staff or Master Gardeners at your nearest Illinois Extension officefor a free consultation from the experts. We're here to help!

Planting Dates for Common Vegetables

Download the printable PDF

Asparagus from Crowns

Northern Illinois: April 1 to 30 |Central Illinois: March 15 to April 15 |Southern Illinois: March 1 to April 1
Sow 12 to 18 inches apart and 6 inches deep. Spread roots and cover crown bud with 2 inches of soil; do not harvestfirst year; mow foliage after fall frost.

Bush Beans from Seed

Northern Illinois: May 24 - June 30 or July 30 - Aug. 14 | Central Illinois:May 10 - June 15 or July 15 - 30 | Southern Illinois: April 26-June 1 or July 1-July 15
Sow 2-4 inches apart and 1 inch deep.

Pole Beans from Seed

Northern Illinois: May 24-June 30 | Central Illinois: May 10 - June 15 | Southern Illinois: April 26 - June 1
Sow4-6" apart, 1" deep.

Beets from Seed

Northern Illinois: April 24-July 30 | Central Illinois: April 10 - July 15 (Fall crop) | Southern Illinois: March 27 - July 30
Sow1" apart, ½" deep.Soak in water 24 hours before planting; thin seedlings to 2" apart.

Broccoli from Transplant

Northern Illinois: April 24-May 15, July 15-30 | Central Illinois: April 10-May 1,July 1-15 | Southern Illinois: March 27 - April 15, July 15-30
Sow¼ - ½" deep, 12-24" apart.

Cabbage from Transplant

Northern Illinois: April 24-July 30 | Central Illinois: April 10 - July 15 (Fall crop)| Southern Illinois: March 27 - July 30
Sow12-24" apart.

Carrots from Seed

Northern Illinois: April 24-July 30 | Central Illinois: April 10 - July 15 (Fall crop)| Southern Illinois: March 27 - July 30
Sow½" apart, ½" deep.Mix with sand or soil to spread seed more evenly; keep moist during germination; thin to 1".

Cauliflower from Transplant

Northern Illinois:July 24 - Aug. 10 | Central Illinois: July 10 - 20 (Fall crop)| Southern Illinois: June 27 - July 6
Sow 18-24" apart.

Chard from Seed or Transplant

Northern Illinois: April 24-June 14, Aug. 1-14 | Central Illinois: April 10 - June 1,July 21 - August 1| Southern Illinois: March 27-May 15, July 7-21
Sow seed 2-4" apart, 1" deep.Thin to 6" if seeded.

Corn from Seed

Northern Illinois: May 15-July 1 | Central Illinois: May 1 - July 9| Southern Illinois: April 15-June 25
Sow12" apart, 1" deep.

Cucumber from Seed

Northern Illinois: May 24-June 30 | Central Illinois: May 10 - June 15| Southern Illinois: April 27-June1
Sow 12" apart, 1" deep.

Eggplant from Transplant

Northern Illinois: May 24-June 30 | Central Illinois: May 10 - June 15| Southern Illinois: April 27-June1
Sow18-24" apart.

Endive from Seed

Northern Illinois: April 14-May14, August 5-30 | Central Illinois: April 1 - May 1,July 21 - August 15 | Southern Illinois: March 15-April 15, July 7-Aug. 1
Broadcast seed.Top dress with ¼" of soil, thin to 9".

Garlic Clove

Best planted in fall
Northern Illinois: mid-September | Central Illinois: October| Southern Illinois: late October
Sow2-4" apart, 1-2" deep.

Kale from Transplant

Northern Illinois: April 14-May 14, August 1-14 | Central Illinois: April 1 - 30,July 21 - August 1| Southern Illinois: March 15-April 15, July 7-18
Seed 6" apart, ½" deep.Thin to 12".

Kohlrabi from Seed

Northern Illinois: April 8-20, July 15 | Central Illinois: March 25 - April 5,July 1| Southern Illinois: March 10-20, June 15
Sow4" apart, ½"deep.

Lettuce from Seed

Northern Illinois: April 15-May 15, July 15-Sept. 15 | Central Illinois: April 1 - 30,July 1 - August 31| Southern Illinois: March 15-April 15, June 15-Aug. 15
Broadcast seed.Top dress with ¼" of soil; thin to 4"; consider shade for late plantings.

Muskmelon from Seed

Northern Illinois: June 3-24 | Central Illinois: May 20 - June 10| Southern Illinois: May 6-28
Sow24" apart, 1" deep.

Mustard Seed

Northern Illinois: April 15-June 15, July 15-Sept. 15 | Central Illinois: April 1 - 30,July 1 - August 31| Southern Illinois: March 15-April 15, June 15-Aug. 15
Sow4" apart, ½"deep.

Okra from Transplant

Northern Illinois: May 24-June 30 | Central Illinois: May 10 - June 15| Southern Illinois: April 26-June 1
Sow12-24" apart.

Onion (green) Sets

Northern Illinois: April 9-May 15 | Central Illinois: March 25 - May 1| Southern Illinois: March 11-April 15
Sow2" apart, 1" deep.

Parsnip from Seed

Northern Illinois: May 15-Aug. 5 (Fall crop) | Central Illinois: May 1 - July 21 (Fall crop)| Southern Illinois: April 15-July 7 (Fall crop)
Sow3" apart, ½" deep.Thin to 18-24".

Peas from Seed

Northern Illinois: April 24-May 15 | Central Illinois: April 10 - May 1| Southern Illinois: March 27-April 15
Sow1" apart, 1" deep.

Pepper from Transplant

Northern Illinois: June 15-July 30 | Central Illinois: June 1 - July 15| Southern Illinois: May 15-June 30
Sow24" apart.

Potato

Northern Illinois: April 15-30 | Central Illinois: April 1 - 15| Southern Illinois: March 15-30
Sow12" apart, 2" deep.

Pumpkin

Northern Illinois: June 3-24 | Central Illinois: May 20 - June 10| Southern Illinois: May 5-25
Sow5 seeds per hill, 1" deep, 3-6' between hills.Thin to 2 or 3 best seedlings.

Radish from Seed

Northern Illinois: April 20-June 15, Aug. 15-Sept. 15 | Central Illinois: April 5 - June 1,August 1 - 30| Southern Illinois: March 20-May 15, July 15-Aug. 15
Sow1-4" apart, ½" deep.

Rhubarb from Roots or Crown Bulbs

Northern Illinois: April 9-May 30, Aug. 3-15 | Central Illinois: March 25 - May 15,July 21 - August 1| Southern Illinois: March 11-May1, July 7-14
Sow2' apart, 2" deep. Rhubarb is a perennial crop.

Rutabaga from Seed

Northern Illinois: May 15-Aug. 5 (Fall crop) | Central Illinois: May 1 - July 21 (Fall crop)| Southern Illinois: April 15-July 7 (Fall crop)
Sow2" apart, 1/2" deep.Thin to 6" when plants are 2" tall.

Spinachfrom Seed

Northern Illinois: April 5-30, Aug. 5-Sept. 15 | Central Illinois: March 25 - April 15,July 21 - August 30| Southern Illinois: March 11-April 1, July 7-Aug. 15
Broadcast seed.Top dress with ½" soil; thin to 2-4.

Squash (summer) from Seed

Northern Illinois: May 24-June 30 | Central Illinois: May 10 - June 15| Southern Illinois: April 28-June 1
Sow2 seeds 24-36" apart, 1" deep.Thin weaker seedlings.

Squash (winter) from Seed

Northern Illinois: June 5-15 | Central Illinois: May 20 - June 1| Southern Illinois: May 6-May 15
Sow4 seeds per hill, 6' between hills, 1" deep.Thin to two strongest seedlings.

Sweet Potato Slips

Northern Illinois: May 24-June 15 | Central Illinois: May 10 - June 1| Southern Illinois: April 28-May 15
Sow12" apart on a raised ridge 8" tall.

Tomato from Transplant

Northern Illinois: May 24-June 15 | Central Illinois: May 10 - June 1| Southern Illinois: April 28-May 15
Sow24-36" apart.Bury transplant up to bottom two leaves.

Turnip from Seed

Northern Illinois: May 15-August 5 (fall crop) | Central Illinois: May 1 - July 21 (Fall crop)| Southern Illinois: April 15-July 7 (Fall crop)
Sow2" apart, ½" deep.Thin to 4" when plants are 4" tall.

Watermelon from Seed

Northern Illinois: ay 24-July 1 | Central Illinois: May 10 - June 15| Southern Illinois: April 28-June 1
Sow3-4 seeds per hole, 4-6' apart, 1" deep.Thin to two strongest seedlings.

Do you know when to plant in Illinois? (2024)

FAQs

When should I start planting in Illinois? ›

Half-hardy vegetables can be planted as early as 2 to 3 weeks before the average date of the last 32 freeze in the spring. Tender vegetables should be planted from the time of the last average 32 freeze to one week later. Very tender crops should be planted 2 to 3 weeks after the last average 32 freeze.

How do you determine when to plant? ›

Timing for all planting is based on first and last frost dates. For example, if planting in hardiness zone 5, the last frost date is generally between April 1st – April 15th, and the first frost date typically falls between October 16th – October 31st. These dates will in part dictate when the best time to plant is.

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When should I plant my flowers in Illinois? ›

Plant warm-season flowering annuals, vines, herbs, and vegetables after the Chicago area's average last frost date of May 15. Cautious gardeners often wait until Memorial Day before setting out cold-sensitive plants such as tomatoes, peppers, eggplants, and squash.

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What is the best time for planting and why? ›

The best time to plant any plant is during the dormant season – in North America, this is usually late fall through early spring. While it's okay to plant during the rest of the year, it will require more maintenance from you in the form of watering, fertilizers, etc.

What should I start planting right now? ›

Plant in the ground: lettuce, carrots, beets, parsnips, potatoes, celeriac, radishes, spinach. Plant in the ground: lettuce (and other salad greens), carrots, beets parsnips, radishes, spinach, purple beans.

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What can I plant in April in Illinois? ›

Plant small transplants of asparagus, early potatoes, lettuce, radish, mustard, onions, peas, rhubarb, spinach, turnips, cauliflower, carrots, and all other cool-season crops as weather permits. Plant midseason potatoes in mid-April.

When should I plant my fall garden? ›

In fall, sow seeds no later than 10 weeks before the first frost for a fall harvest. The seeds are tiny. Sow as evenly as possible but expect to come back after germination to thin out crowed sprouts for proper spacing.

Read On ›

What time should you start planting? ›

Witz suggests starting seeds eight to 12 weeks before your area's last expected frost date. Again, check your seed packet, garden center or local extension office for a plant-specific timeframe.

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Can you plant flowers in 40 degree weather? ›

Flowering annual species and varieties are often divided into two groups: warm season and cool season. Plants in the latter group can be sown when night temperatures are 40 to 50 degrees Fahrenheit and may even be able to stand some frost.

When should I plant tomatoes in Illinois? ›

Considered a warm-season crop because plants need warm soil and frost-free nights, tomatoes are best planted outdoors after mid-May in the Chicago area. Even then you might need to cover plants, which is why many gardeners wait until after Memorial Day to plant.

What is my planting zone in Illinois? ›

This is called a Plant Hardiness Zone. Southern Illinois is in Zones 6a-7a. Central Illinois is in Zones 5a-6a. Northern Illinois is in Zones 5a-5b.

Get More Info ›

What month is the best to start a garden? ›

Generally March and April, when the soil begins to warm, are the best months to begin sowing many hardy annual vegetable seeds outdoors including broccoli, cabbage, chard, carrots, peas and parsnips.

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When should I start planting my garden in Chicago? ›

Chicago is in the USDA Zone 6a, which means that the growing season is generally from late April until early October. But don't wait until the last week of April to begin! To ensure the longest growing season, you'll need to start in March.

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When should I start my outdoor plants? ›

The best time to start seeds is usually late March to late May. Only the southern zones are suitable for starting plants from seed in the earlier months. Give the plant enough time to germinate and grow to an appropriate transplant size.

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