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When to Plant Cilantro in Mineral County, CO

Mineral County, Colorado Zone 5a May

This month in Mineral County, Colorado

Your Mineral County, Colorado garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost June 10
Avg. first frost September 13
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Direct-sow cilantro

    These tolerate cool soil, so you're not gambling by sowing now.

Before June arrives, get these ready
  • Transplants going out: cilantro

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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.

Mineral County, Colorado is in USDA Zone 5a. The average last spring frost is June 10 and the first fall frost is September 13, giving you a growing season of approximately 95 days.

At an elevation of 7,809 feet, Mineral County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, 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.

Mineral County, CO (Zone 5a) Very short season
95 days
Last Spring Frost June 10
95 growing days
First Fall Frost September 13
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Mineral County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Apr 24 Transplant: May 22 🍅 Harvest: Jul 3 – Sep 4
Recommended (50%) ✗ May not fit
Start indoors: May 6 Transplant: Jun 3 🍅 Harvest: Jul 15 – Sep 16
Safe Start (90%) ✗ May not fit
Start indoors: May 22 Transplant: Jun 19 🍅 Harvest: Jul 31 – Oct 2

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.

Soil Compatibility in Mineral County

How your county's soil matches Cilantro's growing requirements.

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Mineral County is excellent for Cilantro — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Cilantro.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Cilantro.

How to Plant Cilantro

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cilantro

2
successive plantings in your 95-day season

Sow every 4.6 weeks. Last sowing by Jul 15 to harvest before frost.

For a dedicated fall crop, sow by Jul 05.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 85 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cilantro

Cilantro needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Cilantro Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.1" 0" ❄️ Dormant
May 1.6" 0" ❄️ Dormant
Jun 2.2" 0.8" 1.4" 🚿 Regular watering
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1.4" 0.8" 💧 Light watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Cilantro Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cilantro needs ~500 GDD — county provides 950 GDD Excellent fit

Cilantro Planting Timeline — Mineral County, CO

Cilantro Planting Calendar

Activity When Date Range
Start Indoors May 6 May 6 – May 20
Transplant Outdoors June 3 Jun 3 – Jun 17
Direct Sow May 27 May 27 – Jun 17
Harvest July 15 Jul 15 – Sep 16
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Start Indoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

95 days in Mineral County

Growing Tips for Cilantro in Mineral County

Direct sow Cilantro outdoors after June 10 in Mineral County when soil has warmed and frost danger has passed.

Common pests for Cilantro in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Mineral County, CO?

Mineral County is in Zone 5a with an average last frost of June 10. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mineral County, CO?

Mineral County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 10 and first fall frost is September 13.

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Your Mineral County Garden Planner — Free

A 24-page printable planner built for Mineral County (Zone 5a). 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 Mineral County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.