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When to Plant Parsley in Henry 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.

Henry County, Illinois is in USDA Zone 5a. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.

At an elevation of 593 feet, Henry County receives approximately 31.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Parsley during the growing season.

Henry County, IL (Zone 5a) Moderate season
183 days
Last Spring Frost April 16
183 growing days
First Fall Frost October 16

Henry County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (65 days to spare)
Start indoors: Mar 6 Transplant: Apr 3 🍅 Harvest: Jun 5 – Aug 7
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 13
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 27 – Aug 29

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 444 gal / 100 sq ft
Parsley needs ~1,068 GDD — county provides 2,790 GDD Excellent fit

Parsley Planting Timeline โ€” Henry County, IL

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 9 Apr 9 โ€“ Apr 23
Direct Sow April 2 Apr 2 โ€“ Apr 23
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest June 11 Jun 11 โ€“ Aug 13

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April 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 5a

Growing Season

183 days

Growing Tips for Henry 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 Henry County, IL?

Henry County is in Zone 5a with an average last frost of April 16. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Henry County, IL?

Henry County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 16 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Henry County gardeners in Zone 5a 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 Henry County, IL. Local conditions may vary. Last updated: April 2026.