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When to Plant Parsley in DuPage County, IL

Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

DuPage County, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.

At an elevation of 803 feet, DuPage County receives approximately 31 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Parsley to ensure they mature before fall.

DuPage County, IL (Zone 5b) Moderate season
177 days
Last Spring Frost April 23
177 growing days
First Fall Frost October 17

DuPage County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: Jun 13 – Aug 15
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 20
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Apr 5 Transplant: May 3 🍅 Harvest: Jul 5 – Sep 6

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 417 gal / 100 sq ft
Parsley needs ~858 GDD — county provides 2,168 GDD Excellent fit

Parsley Planting Timeline โ€” DuPage County, IL

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 9 Apr 9 โ€“ Apr 30
Fall Sowing August 8 Aug 8 โ€“ Aug 22
Harvest June 18 Jun 18 โ€“ Aug 20

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“80 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

177 days

Growing Tips for DuPage County

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Level Up Your Garden

Frequently Asked Questions

When should I plant Parsley in DuPage County, IL?

DuPage County is in Zone 5b with an average last frost of April 23. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is DuPage County, IL?

DuPage County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help DuPage County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for DuPage County, IL. Local conditions may vary. Last updated: April 2026.