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When to Plant Parsley in Marion 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.

Marion County, Illinois is in USDA Zone 6a. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 964 feet, Marion County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Parsley during the growing season.

Marion County, IL (Zone 6a) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Mar 1 Transplant: Mar 29 🍅 Harvest: May 31 – Aug 2
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 6 Transplant: Apr 3 🍅 Harvest: Jun 5 – Aug 7
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Mar 16 Transplant: Apr 13 🍅 Harvest: Jun 15 – Aug 17

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.

Soil Compatibility in Marion County

How your county's soil matches Parsley's growing requirements.

Soil pH

Your soil pH (6.1โ€“7.0) is within Parsley's preferred range (6.0โ€“7.0).

Soil Texture

The silt loam soil in Marion County is excellent for Parsley โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Parsley.

Organic Matter

Organic matter is excellent (4.4%) โ€” Parsley will thrive.

How to Plant Parsley

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Parsley

3
successive plantings in your 192-day season

Sow every 6.9 weeks. Last sowing by Jul 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Parsley

Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Parsley Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr 2.6" 3.4" 0" โœ… Rainfall sufficient
May 2.6" 5" 0" โœ… Rainfall sufficient
Jun 2.6" 5.2" 0" โœ… Rainfall sufficient
Jul 2.6" 3.8" 0" โœ… Rainfall sufficient
Aug 2.6" 4.7" 0" โœ… Rainfall sufficient
Sep 2.6" 3.3" 0" โœ… Rainfall sufficient
Oct 2.6" 3.3" 0" โœ… Rainfall sufficient
Nov โ€” 3.1" 0" โ„๏ธ Dormant
Dec โ€” 2.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Marion County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Parsley Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Parsley needs ~1,172 GDD — county provides 3,216 GDD Excellent fit

Parsley Planting Timeline โ€” Marion County, IL

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 โ€“ Mar 20
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Direct Sow March 27 Mar 27 โ€“ Apr 17
Harvest June 5 Jun 5 โ€“ Aug 7
Fall Sowing August 10 Aug 10 โ€“ Aug 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
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

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

192 days in Marion County

Growing Tips for Parsley in Marion County

Direct sow Parsley outdoors after April 10 in Marion County when soil has warmed and frost danger has passed.

Common pests for Parsley in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsley in Marion County, IL?

Marion County is in Zone 6a with an average last frost of April 10. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marion County, IL?

Marion County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 10 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marion County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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