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When to Plant Parsley in Henderson County, IL

Henderson County, Illinois Zone 6a May

Henderson County, Illinois gardeners: here's your May plan

May is a pivotal month for Henderson County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 17
Avg. first frost October 17
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Sow parsley in trays indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Coming up in June — start thinking about
  • First harvests: parsley

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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.

Henderson County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 1,278 feet, Henderson County receives approximately 41.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Parsley to ensure they mature before fall.

Henderson County, IL (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17
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Henderson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 7 Transplant: Apr 4 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🍅 Harvest: Jun 12 – Aug 14
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 25 – Aug 27

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 Henderson County

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

Soil pH

Your soil pH (5.7–7.3) overlaps with Parsley's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Henderson County is excellent for Parsley — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.6%) — 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 183-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
1.0″/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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.6" 3.9" 0" ✅ Rainfall sufficient
May 2.6" 4.4" 0" ✅ Rainfall sufficient
Jun 2.6" 5.4" 0" ✅ Rainfall sufficient
Jul 2.6" 4.6" 0" ✅ Rainfall sufficient
Aug 2.6" 4.9" 0" ✅ Rainfall sufficient
Sep 2.6" 3.3" 0" ✅ Rainfall sufficient
Oct 2.6" 3.5" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Henderson County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~910 GDD — county provides 2,379 GDD Excellent fit

Parsley Planting Timeline — Henderson County, IL

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 3 Apr 3 – Apr 24
Harvest June 12 Jun 12 – Aug 14
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in Henderson County

Growing Tips for Parsley in Henderson County

Direct sow Parsley outdoors after April 17 in Henderson 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 Henderson County, IL?

Henderson County is in Zone 6a with an average last frost of April 17. Plan your Parsley planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henderson County, IL?

Henderson County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.

🌱

Your Henderson County Garden Planner — Free

A 24-page printable planner built for Henderson County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.