When to Plant Cilantro in Hamilton 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.
Hamilton County, Iowa is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.
At an elevation of 1,210 feet, Hamilton County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Cilantro to ensure they mature before fall.
Hamilton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Cilantro Planting Timeline — Hamilton County, IA
Cilantro Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Fall Sowing | July 15 | Jul 15 – Jul 29 |
| Harvest | June 5 | Jun 5 – Aug 7 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
40–60 days
Soil pH
6 – 7
USDA Zone
Zone 4b
Growing Season
159 days
Growing Tips for Hamilton 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
Level Up Your Garden
Cilantro in Other Locations
Frequently Asked Questions
When should I plant Cilantro in Hamilton County, IA?
Hamilton County is in Zone 4b with an average last frost of May 1. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hamilton County, IA?
Hamilton County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.
Plan Your Garden with Confidence
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