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When to Plant Parsley in Boone 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.

Boone County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.

At an elevation of 950 feet, Boone County receives approximately 30.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Parsley during the growing season.

Boone County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 28
161 growing days
First Fall Frost October 6

Boone County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 19
Recommended (50%) ✓ Fits season (42 days to spare)
Start indoors: Mar 24 Transplant: Apr 21 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Apr 7 Transplant: May 5 🍅 Harvest: Jul 7 – Sep 8

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 342 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Parsley needs ~962 GDD — county provides 2,213 GDD Excellent fit

Parsley Planting Timeline โ€” Boone County, IA

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 โ€“ Apr 7
Transplant Outdoors April 21 Apr 21 โ€“ May 5
Direct Sow April 14 Apr 14 โ€“ May 5
Fall Sowing July 28 Jul 28 โ€“ Aug 11
Harvest June 23 Jun 23 โ€“ Aug 25

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 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

161 days

Growing Tips for Boone 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 Boone County, IA?

Boone County is in Zone 5a with an average last frost of April 28. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Boone County, IA?

Boone County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Boone 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 Boone County, IA. Local conditions may vary. Last updated: April 2026.