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When to Plant Parsley in Worth County, IA

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.

Worth County, Iowa is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 886 feet, Worth County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Parsley to ensure they mature before fall.

Worth County, IA (Zone 4b) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7

Worth County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 21
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 25 – Aug 27
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 10 – Sep 11

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 Worth County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) โ€” Parsley will thrive.

How to Plant Parsley

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Parsley

3
successive plantings in your 160-day season

Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

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 โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr 2.6" 3.7" 0" โœ… Rainfall sufficient
May 2.6" 5" 0" โœ… Rainfall sufficient
Jun 2.6" 4.9" 0" โœ… Rainfall sufficient
Jul 2.6" 4.2" 0" โœ… Rainfall sufficient
Aug 2.6" 4.5" 0" โœ… Rainfall sufficient
Sep 2.6" 3.4" 0" โœ… Rainfall sufficient
Oct 2.6" 3.3" 0" โœ… Rainfall sufficient
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Worth 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 ~910 GDD — county provides 2,080 GDD Excellent fit

Parsley Planting Timeline โ€” Worth County, IA

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest June 25 Jun 25 โ€“ Aug 27
Fall Sowing July 15 Jul 15 โ€“ Jul 29

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 Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August 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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

160 days in Worth County

Growing Tips for Parsley in Worth County

Direct sow Parsley outdoors after April 30 in Worth 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 Worth County, IA?

Worth County is in Zone 4b with an average last frost of April 30. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Worth County, IA?

Worth County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Worth County gardeners in Zone 4b 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 Worth County, IA. Local conditions may vary. Last updated: April 2026.