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When to plant Cilantro in Custer County, CO

The best window to plant Cilantro in Custer County, is May 9–May 30, when soil warms to 50°F. Last frost typically hits May 23; first frost September 25. A second sowing from July 17 to July 31 extends the harvest into fall.

When to Plant Cilantro in Custer County, CO

Cilantro

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.

Custer County, Colorado is in USDA Zone 5b. The average last spring frost is May 23 and the first fall frost is September 25, giving you a growing season of approximately 125 days.

At an elevation of 8,115 feet, Custer County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Cilantro during the growing season. With low rainfall, drip irrigation is essential for growing Cilantro successfully. Mulch heavily to conserve soil moisture.

Custer County, CO (Zone 5b) Short season
125 days
Last Spring Frost May 23
125 growing days
First Fall Frost September 25

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Monthly Watering Guide for Cilantro

Cilantro needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cilantro Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Custer County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cilantro Planting Timeline — Custer County, CO

Cilantro Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 – May 2
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest June 27 Jun 27 – Aug 29
Fall Sowing July 17 Jul 17 – Jul 31

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors 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

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

125 days in Custer County

Growing Tips for Custer 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cilantro in Custer County, CO?

Custer County is in Zone 5b with an average last frost of May 23. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, CO?

Custer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 23 and first fall frost is September 25.

When should I plant Cilantro in Custer County, CO?

In Custer County, CO, plant Cilantro after the last frost (around May 23) and before the first frost (around September 25). Best results when soil holds above 50°F.

What growing zone is Custer County, CO for Cilantro?

Custer County sits in USDA Zone 5b. Cilantro grows reliably in zones 2a through 11b, so it's a good fit here.

Can Cilantro grow in Custer County's climate?

Yes — Cilantro grows well in Custer County's temperate climate. Custer County averages a 125-day frost-free season, with last frost around May 23 and first frost around September 25.

🌱

Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Custer County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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