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When to plant Cumin in Denver County, CO

In Denver County, plant Cumin in spring between April 30 and May 21, once soil temps hold above 50°F. Denver County's last frost averages May 14, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 18 and August 1 — roughly 100–120 days before the first frost on September 26.

When to Plant Cumin in Denver County, CO

Cumin is a warm-season annual herb whose seeds are one of the most widely used spices globally. It requires a long, hot growing season of 3-4 months.

Denver County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 6,818 feet, Denver County receives approximately 20.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Cumin during the growing season.

Denver County, CO (Zone 6a) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Denver County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Monthly Watering Guide for Cumin

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

Month Cumin Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Cumin Planting Timeline — Denver County, CO

Cumin Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest August 20 Aug 20 – Oct 22
Fall Sowing July 18 Jul 18 – Aug 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Denver County

Growing Tips for Denver County

Start seeds indoors 4 weeks before last frost. Transplant after all danger of frost. Harvest when seed heads turn brown. Requires consistent warmth for proper seed development.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cumin in Denver County, CO?

Denver County is in Zone 6a with an average last frost of May 14. Plan your Cumin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Denver County, CO?

Denver County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Cumin in Denver County, CO?

In Denver County, CO, plant Cumin after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Denver County, CO for Cumin?

Denver County sits in USDA Zone 6a. Cumin grows reliably in zones 5a through 11b, so it's a good fit here.

Can Cumin grow in Denver County's climate?

Yes — Cumin grows well in Denver County's temperate climate. Denver County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

🌱

Your Denver County Garden Planner — Free

A 22-page printable planner built for Denver County (Zone 6a). 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 Denver County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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