Blog

When to Plant Cilantro in Poweshiek County, IA

Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.

Poweshiek County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 1,221 feet, Poweshiek County receives approximately 36 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Cilantro during the growing season.

Poweshiek County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Poweshiek County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 29
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 6 – Aug 8
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: Apr 10 Transplant: May 8 🍅 Harvest: Jun 19 – Aug 21

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
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 73 gal / 100 sq ft
Drought risk

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

Cilantro needs ~725 GDD — county provides 2,291 GDD Excellent fit

Cilantro Planting Timeline โ€” Poweshiek County, IA

Cilantro Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 18 Apr 18 โ€“ May 9
Fall Sowing July 29 Jul 29 โ€“ Aug 12
Harvest June 6 Jun 6 โ€“ Aug 8

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

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

158 days

Growing Tips for Poweshiek County

Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Cilantro in Poweshiek County, IA?

Poweshiek County is in Zone 5a with an average last frost of May 2. Plan your Cilantro planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Poweshiek County, IA?

Poweshiek County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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