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When to Plant Cilantro in Duchesne County, UT

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.

Duchesne County, Utah is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 5,302 feet, Duchesne County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Cilantro to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cilantro successfully. Mulch heavily to conserve soil moisture.

Duchesne County, UT (Zone 4b) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Duchesne County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 5 – Aug 7
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 14 – Aug 16
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 9 – Sep 10

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
0.4″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 987 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Cilantro needs ~500 GDD — county provides 1,470 GDD Excellent fit

Cilantro Planting Timeline โ€” Duchesne County, UT

Cilantro Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 โ€“ Apr 12
Transplant Outdoors May 3 May 3 โ€“ May 17
Direct Sow May 3 May 3 โ€“ May 24
Fall Sowing July 12 Jul 12 โ€“ Jul 26
Harvest June 14 Jun 14 โ€“ Aug 16

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
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August 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 4b

Growing Season

147 days

Growing Tips for Duchesne 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 Duchesne County, UT?

Duchesne County is in Zone 4b with an average last frost of May 10. Plan your Cilantro planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Duchesne County, UT?

Duchesne County, Utah is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

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