Author: Jagdish Reddy | 10+ Years Sustainable Gardening Experience
Verification: Cross-referenced with USDA Climate Data & University Research
Status: Verified for current US regional growing conditions
Last Updated: April, 2026

Figuring out when to plant vegetables in Illinois isn’t just about the calendar—it’s about your patch of soil, your town’s last frost, and whether you’re up by Lake Michigan or down near the Ohio River.

This Illinois vegetable planting schedule gives you real timing: what to plant now in Illinois, when to start seeds indoors in Illinois, and how to plan fall crops before summer even peaks.

Structured as a month-by-month Illinois planting calendar, it works whether you’re using a raised bed in Peoria, containers in Chicago, or a backyard plot in Carbondale. You’ll find the best times to plant in Illinois for everything from garlic to zinnias—no guesswork.

This calendar provides Illinois planting timing by season, matching the seasonal planting calendar for Illinois to actual Midwest weather. It’s not generic—it’s tuned to Zones 5a through 7b, with room for both beginners and dirt-under-the-nails veterans.

Not sure which zone you’re in? No worries—just pop your ZIP code into the official USDA Plant Hardiness Zone Map, and boom, you’ll see your frost window right away.

What to Plant in Illinois Right Now (Quick Guide by Region)

Northern Illinois (Zone 5a–5b)

If your soil is workable and temps are warming, you can get cool-season crops going. Warmer-season plants still need indoor time.

• Good to plant outdoors now: peas, spinach, radishes, carrots, lettuce
• Seedlings to start indoors: tomatoes, peppers, cabbage-family crops
• Direct sow soon (as soil warms): beets, Swiss chard, arugula

Central Illinois (Zone 6a–6b)

Central Illinois experiences spring a couple of weeks earlier than the northern regions.

• Ready for outdoor planting: peas, onions (sets), potatoes, greens
• Start indoors now: tomatoes, peppers, basil, broccoli
• Direct sow as weather stabilizes: carrots, beets, radishes, lettuce

Southern Illinois (Zone 7a–7b)

Southern Illinois warms fastest, so planting begins earlier here than anywhere else in the state.

• Plant outdoors now: peas, potatoes, spinach, kale, early lettuce
• Start indoors (final rounds): tomatoes, peppers, eggplant
• Direct sow warm crops soon: beans, squash, cucumbers once nights stay mild

Illinois Frost Dates & Growing Season (Zones 5a–7b)

Spring doesn’t flip on like a switch in Illinois—it creeps up from the south while the north huddles under late frosts. These averages help you avoid planting tomatoes only to lose them to a May dip in Rockford.

Region/Cities	Last Spring Frost	First Fall Frost	Growing Season (Days)
Northern: Chicago, Rockford, Waukegan, Elgin	Apr 20 – May 10	Oct 1 – Oct 15	140–160
Central: Springfield, Peoria, Champaign, Decatur	Apr 10 – Apr 30	Oct 15 – Oct 30	160–180
Southern: Carbondale, Cairo, Belleville, Marion	Mar 25 – Apr 15	Nov 1 – Nov 15	180–210

Month-by-Month Planting Guide for Illinois

Month	Vegetables	Herbs	Flowers	Indoors / Outdoors
Jan	Onions (seeds), leeks, celery	Rosemary (potted), thyme	Pansy seeds, snapdragons	Indoors
Feb	Tomatoes, peppers, eggplant, broccoli, cabbage, cauliflower, Brussels sprouts, kale, collards	Basil, parsley, cilantro, dill	Marigolds, zinnias, cosmos, cleome	Indoors
Mar	Lettuce, spinach, Swiss chard, fennel, kohlrabi	Chives, mint, oregano, sage, lemon balm	Nasturtiums, sweet peas, calendula, larkspur	Indoors / Cold frame
Apr	Peas, radishes, carrots, beets, turnips, potatoes, onions (sets), spinach, arugula	Parsley, cilantro, dill, chervil	Pansies, alyssum, snapdragons, bachelor’s buttons, poppies	Outdoors
May	Green beans, lima beans, corn, cucumbers, squash, zucchini, melons, okra, sweet potatoes	Basil (out), tarragon, lemon verbena	Zinnias, marigolds, sunflowers, cosmos, salvia	Outdoors
Jun	Pumpkins, winter squash, okra, southern peas, tomatillos	Cilantro (resow), borage, fennel	Black-eyed Susans, coreopsis, lantana, bee balm	Outdoors
Jul	Fall: broccoli, cauliflower, kale, collards, cabbage, beets, turnips, radicchio, endive, spinach (late)	Dill, parsley, winter savory	Coneflowers, phlox, yarrow, rudbeckia	Outdoors
Aug	Garlic prep, spinach, mâche, corn salad, arugula (fall), fava beans (S. IL)	Parsley, chives, thyme (fall)	Asters, mums (starts), ornamental kale	Outdoors
Sep	Garlic (plant cloves), spinach, kale, collards, fava beans (S. IL)	Oregano, sage, thyme	Mums, ornamental cabbage, asters	Outdoors
Oct	Cover crops: winter rye, crimson clover, hairy vetch	Dry/store herbs	Fall cleanup	Outdoors
Nov	—	Preserve, dry herbs	Mulch perennials	Outdoors
Dec	Plan garden, order seeds	Organize dried herbs	—	Indoors

Garden Planner Tool

Plan your garden layout using this interactive planner. Enter your garden size to calculate plant spacing and planting timing based on this planting calendar.

This planner helps turn the planting calendar above into a practical garden layout based on your available space.

Illinois USDA Zone Planting Windows

Illinois stretches from near-Canadian winters in Galena (Zone 5a) to almost Ozark-like warmth in Cairo (Zone 7b)—so your planting dates really depend on your zip code, not just the season.

USDA Zone	Cool-Season Window	Warm-Season Window
5a–5b	Late March–mid-April	Mid-May – early June
6a–6b	Early March–early April	Early May–late May
7a–7b	Mid-Feb – early April	Late April–mid-May

Illinois Climate Region Planting Guide

Region	Climate Notes	Cool-Season Start	Warm-Season Start
Northern IL	Lake Michigan delays warming; cooler nights	Late March	Mid-May
Central IL	Classic Midwest prairie climate	Early March	Early May
Southern IL	Humid, long season; borderline Zone 7	Mid-February	Late April

Illinois Soil Type & Crop Match Guide

Up north, my clay held water like a bathtub—great for moisture, terrible for drainage. In the downstate region, sandy loam requires more frequent watering, but it promotes significantly better root growth. Matching crops to your soil saves heartache.

Region	Soil Type	Best Vegetables	Best Flowers	Best Herbs
Northern	Heavy clay, alkaline	Raised beds: lettuce, kale, peas, radishes, carrots	Sedum, black-eyed Susans, yarrow	Thyme, sage, oregano (in pots)
Central	Rich prairie loam	Tomatoes, corn, beans, squash, potatoes	Sunflowers, zinnias, coneflowers	Basil, parsley, mint, cilantro
Southern	Sandy loam, slightly acidic	Sweet potatoes, okra, eggplant, peppers	Lantana, salvia, celosia	Rosemary, fennel, lemon balm

Illinois Vegetable Timing (Crop-by-Crop Guide)

Most Illinois gardeners end up planting tomatoes sometime in the first three weeks of May, once nights reliably stay above 50°F. This guide gives both the ideal window and the reality most of us live with.

Crops	Start Indoors	Transplant Out	Direct Sow	Days to Harvest
Tomatoes	Feb 15–Mar 15	May 1–20	—	60–85
Peppers	Feb 15–Mar 10	May 10–25	—	65–90
Eggplant	Mar 1–15	May 15–30	—	70–85
Cucumbers	Apr 1–15	May 10–25	May 1–15	50–70
Zucchini	Apr 1–15	May 10–20	May 1–10	40–60
Pumpkins	Apr 15–May 1	May 15–30	May 15–Jun 15	90–120
Green Beans	—	—	May 1–Jun 15	50–60
Lima Beans	—	—	May 15–Jun 10	65–80
Sweet Corn	—	—	Apr 20–May 20 (N), Apr 15–May 15 (S)	60–90
Carrots	—	—	Mar 15–Apr 15, Aug 1	50–80
Beets	—	—	Mar 20–Apr 20, Jul 15	50–60
Radishes	—	—	Mar 15–May 1, Aug–Sep	25–35
Lettuce	Feb–Mar	Apr 1–15	Mar–Apr, Aug–Sep	45–60
Spinach	Feb (indoor)	—	Mar 1–Apr 10, Sep 1–Oct 15	40–50
Kale	Feb–Mar	Apr 15–May 1	Apr–May, Aug	55–75
Collards	Feb–Mar	Apr 15–May 1	Apr–May	60–80
Broccoli	Feb–Mar	Apr 15–May 1	—	60–100
Cauliflower	Feb–Mar	Apr 20–May 5	—	50–100
Brussels Sprouts	Feb 15–Mar 1	Apr 15–May 1	—	90–110
Cabbage	Feb–Mar	Apr 15–May 1	Apr 1–15	70–100
Swiss Chard	Mar	Apr 15–May 1	Apr 1–15	50–60
Celery	Jan 15–Feb 15	May 10–25	—	100–130
Leeks	Jan 15–Feb 15	Apr 15–May 15	—	120–150
Onions (seeds)	Jan 15–Feb 15	Apr 1–15	Mar 15–Apr 15	100–120
Onions (sets)	—	—	Mar 15–Apr 15	60–90
Garlic	—	—	Oct 1–15 (cloves)	Harvest Jul–Aug
Fava Beans	—	—	Mar 1–15 (N), Feb 15–Mar 15 (S)	75–100
Arugula	Feb–Mar	Apr 1–15	Mar–Apr, Aug–Sep	30–50
Kohlrabi	Feb–Mar	Apr 15–May 1	Apr 1–15	45–60
Parsnips	—	—	Apr 1–15	100–120

When to Start Seeds Indoors in Illinois (Seed Starting Calendar)

Crops	Start Indoors	Move Outdoors	Notes
Tomatoes	Feb 15–Mar 15	After last frost	Harden off 7–10 days
Peppers	Feb 15–Mar 10	May 10–25	Use heat mat—slow germinators
Eggplant	Mar 1–15	May 15–30	Needs warmth; sensitive to shock
Broccoli	Feb 15–Mar 1	Apr 15–May 1	Tolerates light frost after hardening
Cauliflower	Feb 15–Mar 1	Apr 20–May 5	Needs steady temps
Cabbage	Feb 15–Mar 1	Apr 15–May 1	Cold-hardy
Kale	Feb 15–Mar 1	Apr 15–May 1	Boosts yield
Collards	Feb 15–Mar 1	Apr 15–May 1	Hardy spring/fall crop
Brussels Sprouts	Feb 15–Mar 1	Apr 15–May 1	Long season—must start early
Lettuce	Feb 1–Mar 15	Apr 1–15 (spring); Aug 1 (fall)	Sow every 2 weeks indoors
Celery	Jan 15–Feb 15	May 10–25	Very slow; needs consistent moisture
Leeks	Jan 15–Feb 15	Apr 15–May 15	Thin to pencil thickness
Onions (from seed)	Jan 15–Feb 15	Apr 1–15	Plant deep for longer shank
Parsley	Feb 1–Mar 1	Apr 1–15	Soak seeds; germinates slowly
Basil	Mar 15–Apr 1	May 10–25	Don’t start before Mar—gets leggy
Marigolds	Mar 15–Apr 1	May 1–15	Easy; deters pests
Zinnias	Apr 1–15	May 10–20	Helpful in northern IL
Snapdragons	Feb 15–Mar 15	Apr 15–May 1	Cold-tolerant; early color
Pansies	Jan–Feb	Mar 15–Apr 15	Survive light frost

What to Plant Directly in the Ground in Illinois (Direct Sowing Guide)

Crops	First Sow	Succession Planting	Best Soil Temp
Peas	Mar 15–Apr 15	One crop only	40–75°F
Radishes	Mar 15	Every 10–14 days until May; again Aug 15	45–85°F
Carrots	Mar 20	Every 3 weeks until Jul 1	55–85°F
Beets	Mar 25	Every 3 weeks until Jul 15	50–85°F
Spinach	Mar 1	Apr 15 (if missed); Aug 15–Sep 15	45–70°F
Arugula	Mar 15	Every 2 weeks until May; Aug 1–Sep 15	45–70°F
Lettuce	Mar 15	Every 2 weeks until May; Aug 1–Sep 15	45–75°F
Kale	Apr 1	Aug 1–15	50–85°F
Collards	Apr 1	Aug 1	55–85°F
Green Beans	May 1	Every 2 weeks until Jul 15	60–95°F
Lima Beans	May 15	One crop	70–85°F
Cucumbers	May 10	Every 3 weeks until Jul 1	70–95°F
Squash/Zucchini	May 10	One or two sowings	70–95°F
Corn	Apr 20 (N), May 1 (S)	One crop (block planting)	55–95°F
Okra	May 25 (C), May 15 (S)	Jun 1–15	70–95°F
Parsnips	Apr 1	One crop only	50–70°F
Fava Beans	Mar 1 (N), Feb 15 (S)	One spring crop	40–70°F
Dill	Apr 15	Jul 15 (for fall)	60–70°F
Cilantro	Apr 1	Jul 15	55–68°F

Illinois Warm-Season Crop Timing

Crops	Min Soil Temp	Planting Window	Frost Risk Notes
Tomatoes	60°F	May 1–25	Killed instantly by frost
Peppers	65°F	May 10–30	Extremely frost-sensitive
Eggplant	70°F	May 15–30	Needs consistent warmth
Cucumbers	60°F	May 10–Jun 10	No frost tolerance
Squash/Zucchini	60°F	May 10–20	Wilts in cold
Green Beans	60°F	May 1–Jun 15	Seeds rot in cold, wet soil
Lima Beans	70°F	May 15–Jun 10	Requires long, hot season
Corn	55°F	Apr 20–May 20 (N), Apr 15–May 15 (S)	Tender seedlings
Sweet Potatoes	70°F	Jun 1–15	Needs 90+ warm days
Okra	65°F	May 15–Jun 15	Thrives in heat
Melons	70°F	May 15–Jun 1	Needs full sun

Illinois Flower Planting Calendar

Flowers	Start Indoors	Direct Sow	Bloom Time
Marigolds	Mar 15–Apr 1	May 1–15	Jun–Oct
Zinnias	Apr 1–15	May 10–20	Jul–Oct
Sunflowers	—	May 1–15	Jul–Sep
Pansies	Jan–Feb	Mar 15–Apr 15	Apr–Jun & Sep–Nov
Nasturtiums	—	Apr 15–May 1	Jun–Oct
Cosmos	Apr 1–15	May 10–20	Jul–Oct
Cleome	Mar 15–Apr 1	May 10–20	Jul–Oct
Snapdragons	Feb 15–Mar 15	Apr 1–15	May–Jun
Larkspur	Feb–Mar	Mar 15–Apr 1	May–Jul
Bachelor’s Buttons	Feb–Mar	Mar 15–Apr 15	May–Jul
Sweet Peas	Feb–Mar	Mar 15–Apr 15	May–Jun
Black-eyed Susans	Feb–Mar	Apr 1–May 1	Jul–Sep
Coneflowers	Feb–Mar	Apr–May	Jun–Oct
Coreopsis	Feb–Mar	Apr–May	Jun–Sep
Asters	Feb–Mar	Apr–May	Aug–Oct
Mums	—	Apr–May	Sep–Oct
Bee Balm	Feb–Mar	Apr–May	Jul–Aug
Yarrow	Feb–Mar	Apr–May	Jun–Sep

Illinois Herb Planting Guide

Herbs	Start Indoors	Plant Outdoors	Harvest Window
Basil	Mar 15–Apr 1	May 10–25	Jun–Sep
Parsley	Feb 1–Mar 1	Apr 1–15	Apr–Oct
Cilantro	—	Mar 15 & Aug 1	Apr–May, Sep–Oct
Dill	—	Apr 15 & Jul 15	May–Jun, Aug–Sep
Mint	Feb	Apr 15	May–Oct (grow in pots!)
Thyme	Feb–Mar	Apr 15	Jun–Oct
Oregano	Feb–Mar	Apr 15	Jun–Sep
Chives	Jan–Feb	Mar 15	Apr–Oct
Sage	Feb–Mar	Apr 15	Jun–Sep
Rosemary	Jan–Feb (potted)	May 15 (or keep indoors)	Year-round (Zone 6b+)
Lemon Balm	Feb–Mar	Apr 15	May–Sep
Tarragon	Feb–Mar	Apr 15	Jun–Aug
Fennel	Feb–Mar	Apr 15	Jun–Sep
Chervil	Feb	Mar 15	Apr–Jun
Winter Savory	Feb–Mar	Apr 15	Jun–Sep
Borage	—	May 1	Jun–Aug

Illinois Native Plant Guide (Pollinator-Friendly Picks)

Native Plants	Type	Best Time to Plant	Wildlife Benefit
Purple Coneflower	Perennial	Apr–May or Sep–Oct	Bees, butterflies, birds
Black-eyed Susan	Perennial	Apr–May	Butterflies, seed-eating birds
Wild Bergamot (Bee Balm)	Perennial	Apr–May	Bees, hummingbirds
Common Milkweed	Perennial	Apr–May or Oct	Monarch butterfly host
Butterfly Weed	Perennial	Apr–May	Monarchs, native bees
Joe-Pye Weed	Perennial	Apr–May	Butterflies
Coreopsis	Perennial	Apr–May	Bees, small pollinators
Little Bluestem	Ornamental grass	Apr–May or fall	Birds, nesting material
Goldenrod	Perennial	Apr–May	Late-season pollinators
Wild Columbine	Perennial	Apr–May	Hummingbirds

Illinois Wildlife-Friendly Planting Guide

Plants	Attracts	Planting Time	Notes
Sunflowers	Finches, chickadees, bees	May	Leave seed heads standing in winter
Coneflowers	Goldfinches, bees	Apr–May	Don’t deadhead in fall
Milkweed	Monarch butterflies	Apr or Oct	Essential host plant
Serviceberry	Robins, cedar waxwings	Fall (bare root)	Early spring berries
Elderberry	Cardinals, pollinators	Fall or early spring	Plant 2+ for fruit
Bee Balm	Hummingbirds, bumblebees	Apr–May	Resists deer; spreads easily
Asters	Bees, butterflies	Apr–May	Critical late-season nectar
Native Sumac	Birds, pollinators	Fall	Provides winter berries

Illinois Balcony & Container Gardening Timing

Crops/Flowers	Container Size	Planting Window	Sunlight	Notes
Tomatoes	5+ gallons	May 10–20	Full sun	Use cages; water daily
Peppers	3–5 gallons	May 10–25	Full sun	Well-drained mix
Eggplant	5 gallons	May 15–30	Full sun	Needs consistent warmth
Basil	1–2 gallons	May 10+	Full sun	Pinch tips to bush
Parsley	1 gallon	Apr 15	Part to full sun	Cold-tolerant
Lettuce	Shallow 6″ pot	Apr 1 & Aug 1	Part sun	Great for shade
Spinach	6–8″ deep	Apr 1 & Aug 15	Part sun	Harvest outer leaves
Marigolds	1 gallon	May 1–15	Full sun	Compact varieties
Zinnias	2+ gallons	May 10–20	Full sun	Cut weekly for more blooms
Kale	3 gallons	Apr 15 & Aug 1	Full to part sun	Cold-hardy
Herbs (mix)	Window box	Apr 15–May 1	6+ hrs sun	Avoid mint in mixes
Strawberries	1 gallon/plant	Apr 15	Full sun	Everbearing types
Dwarf Sunflowers	3+ gallons	May 1	Full sun	‘Sunspot’ or ‘Teddy Bear’

Monthly Container Care Guide for Illinois

Pots dry out faster than garden beds—especially on windy Chicago balconies—so adjust care month by month to keep things thriving.

Month	What to Plant	Care Tips	Fertilizer Schedule
Mar	Start tomatoes and peppers indoors	Water lightly; use grow lights	Weekly seed starter feed
Apr	Move parsley and kale outside	Harden off seedlings; protect from wind	Begin mild liquid feed
May	Plant warm crops after frost	Water daily if hot; add mulch	Every 7–10 days
Jun	Add marigolds, zinnias	Check for aphids; stake tall plants	Weekly feeding
Jul	Succession sow lettuce in shade	Water morning & evening	Continue weekly feed
Aug	Plant fall kale, spinach	Move to partial shade if wilting	Switch to balanced feed
Sep	Mums, ornamental kale	Reduce watering	Last fertilizer by mid-Sep
Oct	Bring rosemary and bay indoors	Clean pots; trim leggy growth	Stop fertilizing

Illinois Watering Timings

Month	Watering Needs	Rainfall Notes	Container Adjustments
Apr	Moderate (1″ per week)	Often rainy	Check drainage; don’t let sit in saucers
May	Moderate to high	Rain tapers off	Water every 2–3 days
Jun	High (1–1.5″)	Heat builds	Water daily if >80°F
Jul	Very high (1.5–2″)	Hottest month	Water morning & evening if wilting
Aug	High	Humidity helps, but heat stress continues	Mulch pots; shade afternoon sun
Sep	Moderate	Cooling temps	Reduce to every 2–3 days
Oct	Low	Natural rainfall usually sufficient	Water only if dry
Nov–Mar	Minimal	Snow provides moisture	Only water indoor plants

Illinois Pest & Disease Timing

Pests/Diseases	Active Months	Affected Crops	Prevention Timing
Cutworms	Apr–May	Tomatoes, peppers, cabbage	Collars at transplant
Aphids	May–Sep	Lettuce, kale, beans, flowers	Spray with water; encourage ladybugs
Squash Vine Borer	Jun–Jul	Squash, zucchini	Row cover until bloom
Japanese Beetles	Jul–Aug	Roses, grapes, beans	Hand-pick early morning
Tomato Hornworm	Jun–Aug	Tomatoes, peppers	Inspect weekly
Cabbage Moth	Apr–Jun, Aug–Sep	Broccoli, kale	Row cover; check eggs
Mildew (Powdery)	Jul–Sep	Zucchini, cucumbers, phlox	Space plants; water at base
Blight (Early/Late)	Jun–Sep	Tomatoes, potatoes	Rotate crops; mulch
Slugs	Apr–May, Sep–Oct	Lettuce, hostas	Beer traps; diatomaceous earth
Corn Earworm	Jul–Aug	Sweet corn	Apply mineral oil to silks

Monthly Garden Task Guide for Illinois

Gardening isn’t just planting—it’s a rhythm of tending, harvesting, and prepping. This keeps me from getting overwhelmed in the chaos of July.

Month	Key Tasks	What’s Ready to Harvest	Cleanup Focus
Jan	Order seeds, plan rotation	Stored onions, garlic	Sharpen tools
Feb	Start seeds indoors	—	Clean pots, sanitize trays
Mar	Prep beds, test soil	Overwintered kale, spinach	Remove winter debris
Apr	Plant peas, potatoes, greens	Rhubarb, asparagus, spinach	Weed early beds
May	Transplant tomatoes, peppers	Radishes, lettuce, peas	Stake tall flowers
Jun	Hill potatoes, side-dress corn	Strawberries, lettuce, onions	Thin carrots, beets
Jul	Water deeply, harvest daily	Zucchini, beans, tomatoes	Remove bolting lettuce
Aug	Plant fall crops, shade greens	Tomatoes, peppers, corn	Prune tomato suckers
Sep	Plant garlic, cover crops	Peppers, eggplant, squash	Start compost pile
Oct	Harvest final tomatoes	Pumpkins, winter squash	Pull spent plants
Nov	Mulch perennials, plant bulbs	Kale, collards	Drain hoses, store tools
Dec	Review garden journal	Stored root crops	—

Illinois Harvest Timing Guide

There’s nothing like eating a sun-warmed tomato in July or pulling sweet carrots after a light frost in October. Timing your harvest right makes flavors pop.

Crops	Start Harvest	Peak Season	Final Harvest
Asparagus	Apr 15–May 15 (N), Apr 1–May 1 (S)	May	May 31
Rhubarb	Apr 15–May 1	May–Jun	Jul 1
Spinach	Apr 15–May 15, Sep 15–Nov 15	May & Oct	Hard freeze
Lettuce	Apr 20–May 20, Aug 20–Nov 10	May & Sep	Bolts in heat
Radishes	Apr 15–May 15	May	May 30
Peas	May 15–Jun 15	Jun	Jul 1
Strawberries	Jun 1–15 (N), May 15–Jun 1 (S)	Jun	Jun 30
Zucchini	Jun 15–Jul 10	Jul–Aug	First frost
Green Beans	Jul 1–10	Jul–Aug	First frost
Cucumbers	Jul 1	Jul–Sep	First frost
Tomatoes	Jul 15–Aug 1	Aug–Sep	First frost
Peppers	Aug 1	Aug–Sep	First frost
Eggplant	Aug 10	Aug–Sep	First frost
Corn	Jul 15 (S), Aug 1 (N)	Aug	Aug 30
Melons	Aug 1 (S), Aug 15 (N)	Aug–Sep	First frost
Carrots	Jun 15 (baby), Sep 15 (storage)	Oct	Ground freeze
Beets	Jun 1 (baby), Sep 15 (storage)	Oct	Ground freeze
Potatoes	Jul 1 (new), Sep 15 (storage)	Sep–Oct	Before hard freeze
Sweet Potatoes	Sep 15	Oct	Before 50°F soil
Winter Squash	Sep 1	Sep–Oct	Before hard frost
Pumpkins	Sep 15	Oct	Before hard frost
Kale	May 1	Sep–Nov	Survives light frost
Collards	May 15	Oct–Nov	Survives into Dec in S. IL
Garlic	Jul 1–15	Jul	Cure by Aug 1

Illinois Raised Bed Planting Timeline

Raised beds in clay-heavy northern Illinois warm up 2–3 weeks faster than ground-level soil—so treat them like a mini southern zone.

Crops	Planting Window	Bed Depth	Soil Mix Tips
Tomatoes	May 1–15	12″+	Mix compost, peat, and perlite; pH 6.2–6.8
Peppers	May 10–20	12″+	Well-drained; add aged manure
Lettuce	Apr 1 & Aug 1	6″+	Lightweight mix; stays cool
Carrots	Apr 1 & Aug 1	12″+	Sandy loam; no rocks
Radishes	Mar 20 & Aug 15	6″+	Fast; great for interplanting
Spinach	Mar 15 & Sep 1	8″+	High nitrogen; keep moist
Beans	May 1–15	12″+	Don’t over-fertilize
Cucumbers	May 10	12″+	Add trellis; rich compost base
Kale	Apr 15 & Aug 1	10″+	Tolerant; thrives in raised beds
Strawberries	Apr 15	8″+	Slightly acidic; good drainage
Herbs (perennial)	Apr 15	10″+	Gritty mix for thyme, rosemary
Garlic	Oct 1–15	8″+	Plant cloves 4″ deep; mulch heavily

Illinois Lawn & Grass Planting Guide

Grass Types	Best Planting Time	Overseeding Time	Notes
Tall Fescue (cool-season)	Aug 15–Sep 15	Sep 1–15	Best for sun to part shade; drought-tolerant
Kentucky Bluegrass	Aug 15–Sep 15	Sep 1–15	Needs full sun; slower establishment
Fine Fescue	Aug 15–Sep 15	Sep 1–15	Ideal for shade; low maintenance
Zoysia (warm-season)	May 15–Jun 15	Not recommended	Only for southern IL; slow to green
Buffalograss (native)	May 1–Jun 1	—	Drought-tolerant, low-mow lawn for sun

Never plant cool-season grass in spring—summer heat kills seedlings. Fall is the only reliable window.

Illinois Drought-Tolerant Planting Calendar

Plants	Type	Planting Window	Drought Notes
Lavender	Perennial herb	Apr 15–May 15	Needs sharp drainage
Russian Sage	Perennial	Apr–May	Silvery foliage; blooms all summer
Sedum	Succulent perennial	Apr–May or Sep	Stores water in leaves
Black-eyed Susan	Native perennial	Apr–May	Deep roots; blooms in poor soil
Coneflower	Native perennial	Apr–May	Survives dry spells once established
Yarrow	Perennial	Apr–May	Ferny foliage; tolerates neglect
Coreopsis	Perennial	Apr–May	Cheerful yellow blooms; low water
Thyme	Herb	Apr 15	Creeping varieties great for ground cover
Oregano	Herb	Apr 15	Let soil dry between waterings
Little Bluestem	Native grass	Apr–May or fall	Turns copper in fall; zero irrigation

Illinois Shade Garden Plant Guide

Plants	Shade Level	Planting Window	Notes
Hostas	Full to part shade	Apr–May	Slugs love them—use traps
Ferns (Ostrich, Cinnamon)	Full shade	Apr–May	Native; loves moist soil
Astilbe	Part to full shade	Apr–May	Needs consistent moisture
Heuchera (Coral Bells)	Part shade	Apr–May	Colorful foliage; drought-tolerant
Bleeding Heart	Part shade	Apr	Dies back in summer; mark spot
Solomon’s Seal	Full shade	Apr	Native; spreads slowly
Wild Ginger	Full shade	Apr	Ground cover; native; deer-resistant
Lungwort	Part shade	Apr–May	Early spring blooms; dry shade tolerant
Mint	Part shade	Apr 15	Grows aggressively—plant in pots
Parsley	Part shade	Apr 15	Better flavor with some sun

Illinois Deer-Resistant Plant Guide

Plants	Type	Planting Window	Notes
Lavender	Herb	Apr 15–May 15	A strong scent deters deer
Sage	Herb	Apr 15	Fuzzy leaves unappealing
Oregano	Herb	Apr 15	Spreading; aromatic
Daffodils	Bulb	Oct–Nov	Toxic; deer avoid
Alliums	Bulb	Oct–Nov	Onion family—deer hate smell
Bee Balm	Native perennial	Apr–May	Spreads and attracts pollinators
Yarrow	Perennial	Apr–May	Tough; drought-tolerant
Foxglove	Biennial	Apr–May	Toxic; use caution with kids/pets
Hellebores	Perennial	Apr	Winter/early spring bloom; toxic
Ferns	Native perennial	Apr–May	Generally ignored

Illinois Fruit Tree Planting Guide

Fruit Trees	Planting Window	Chill Hours	Notes
Apple (Honeycrisp, Gala)	Mar 15–Apr 15	800–1000	Needs pollinator partner
Pear (Bartlett, Moonglow)	Mar 15–Apr 15	700–900	Fire blight-resistant varieties
Cherry (Sour: Montmorency)	Mar 15–Apr 15	700–800	Sweet cherries struggle in Zone 5
Plum (Methley, Stanley)	Mar 15–Apr 15	400–700	Methley is self-fertile; Stanley needs a partner.
Peach (Reliance, Contender)	Mar 15–Apr 15	600–900	Only reliable in Zone 6b–7b
Pawpaw (native)	Mar 15–Apr 15	400–600	Needs two trees; shade-tolerant young
Serviceberry	Mar 15–Apr 15	400+	Native; edible berries; multi-trunk
Elderberry	Mar 15–Apr 15 or Oct–Nov	Low	Plant 2+ for fruit; great for jam
Raspberry (Summer & Fall)	Mar 15–Apr 15 or Oct–Nov	None	Fall-bearing easier in IL
Strawberry (June-bearing)	Apr 15	None	Replace every 3 years

Illinois Compost & Soil Improvement Guide

• Layer compost like lasagna:
  • Winter: kitchen scraps
  • Summer: grass clippings
  • Fall: fallen leaves
• Start a compost pile in early spring or fall using a 3:1 ratio of browns (dry leaves, straw) to greens (food scraps, fresh clippings).
• Turn the pile every 2–4 weeks to speed decomposition.
• Insulate your bin with straw in early spring—compost heats slowly in Illinois’ cool spring temps.
• Never compost diseased plants, meat, dairy, or pet waste.
• Apply finished compost to garden beds in April (before planting) and September (for fall crops or soil renewal) to boost fertility and water retention.

8 Common Questions about Planting Calendar for Illinois

1. When is the best time to plant tomatoes in Illinois?
Most gardeners plant between May 5 and May 20, once nights stay above 50°F. Northern IL: lean toward May 15–25. Southern IL: as early as Apr 15.

2. Can I grow okra in Illinois?
Yes—especially in central and southern IL. Direct-sow May 15–Jun 1. It requires over 90 warm days, making it less reliable in northern areas.

3. What vegetables grow well in northern Illinois?
Kale, spinach, peas, carrots, lettuce, and early tomatoes (like ‘Early Girl’ or ‘Stupice’) do best.

4. When should I plant garlic in Illinois?
Plant cloves October 1–15. Mulch heavily. Harvest in July, when the lower leaves are yellow.

5. Can I start seeds outdoors in March in Illinois?
Only in southern Illinois is this possible. North and central: wait until late March–early April for peas, spinach, and radishes—when soil is workable and above 40°F.

6. What flowers bloom all summer in Illinois?
Zinnias, marigolds, coneflowers, black-eyed Susans, and (in the south) lantana bloom from June through first frost.

7. When is the last frost date in Chicago?
The average last spring frost is May 10, but many gardeners wait until May 15 to be safe with tender crops.

8. How do I extend the growing season in Illinois?
Use row covers, cold frames, and mulch for fall crops. Use black plastic to warm the soil in the spring. Choose cold-tolerant varieties like ‘Lacinato’ kale or ‘Winter Density’ lettuce.

Data sources

USDA Plant Hardiness Zone Map
NOAA Frost Probability Data
University of Illinois Extension Planting Guides

Additional Regional Calendars

Check out our planting calendars for other states: