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When to Plant Cilantro in Jackson 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.

Jackson County, Iowa is in USDA Zone 5a. The average last spring frost is April 17 and the first fall frost is October 16, giving you a growing season of approximately 182 days.

At an elevation of 1,321 feet, Jackson County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Cilantro during the growing season.

Jackson County, IA (Zone 5a) Moderate season
182 days
Last Spring Frost April 17
182 growing days
First Fall Frost October 16

Jackson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Mar 7 Transplant: Apr 4 🍅 Harvest: May 16 – Jul 18
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🍅 Harvest: May 22 – Jul 24
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 29 Transplant: Apr 26 🍅 Harvest: Jun 7 – Aug 9

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 308 gal / 100 sq ft
Cilantro needs ~688 GDD — county provides 2,502 GDD Excellent fit

Cilantro Planting Timeline โ€” Jackson County, IA

Cilantro Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 โ€“ Mar 27
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow April 3 Apr 3 โ€“ Apr 24
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest May 22 May 22 โ€“ Jul 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
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

182 days

Growing Tips for Jackson 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 Jackson County, IA?

Jackson County is in Zone 5a with an average last frost of April 17. Plan your Cilantro planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, IA?

Jackson County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 17 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

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