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When to Plant Cumin in Carbon County, WY

Carbon County, Wyoming Zone 5a May

What to do in May

A quick May briefing for Carbon County, Wyoming gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 31
Avg. first frost September 18
Soil temp (4") 30°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Time to transplant cumin

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Scatter cumin into prepared beds

    Your soil is 30°F — warm enough for these to germinate without babying.

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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.

Carbon County, Wyoming is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 18, giving you a growing season of approximately 110 days.

At an elevation of 8,469 feet, Carbon County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Cumin to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cumin successfully. Mulch heavily to conserve soil moisture.

Carbon County, WY (Zone 5a) Short season
110 days
Last Spring Frost May 31
110 growing days
First Fall Frost September 18
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Carbon County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 21 Transplant: May 19 🍅 Harvest: Sep 1 – Nov 3
Recommended (50%) ✗ May not fit
Start indoors: Apr 26 Transplant: May 24 🍅 Harvest: Sep 6 – Nov 8
Safe Start (90%) ✗ May not fit
Start indoors: May 8 Transplant: Jun 5 🍅 Harvest: Sep 18 – Nov 20

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 Carbon County

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

Soil pH

Your soil pH (6.7–8.3) overlaps with Cumin's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Cumin.

How to Plant Cumin

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

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cumin

Cumin 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 Cumin Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 2.2" 2" 0.2" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1.3" 0.9" 💧 Light watering
Aug 2.2" 1.5" 0.7" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Cumin 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.

Cumin needs ~1,100 GDD — county provides 1,100 GDD Tight fit

Cumin Planting Timeline — Carbon County, WY

Cumin Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 – May 10
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 17 May 17 – Jun 7
Harvest September 6 Sep 6 – Nov 8
Fall Sowing July 10 Jul 10 – Jul 24

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 Transplant Outdoors Direct Sow
July Fall Sowing
August
September Harvest
October Harvest
November Harvest
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

110 days in Carbon County

Growing Tips for Cumin in Carbon County

Direct sow Cumin outdoors after May 31 in Carbon County when soil has warmed and frost danger has passed.

Your 110.0-day growing season in Carbon County is tight for Cumin (100.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Carbon County receives only 15" of rain annually. Cumin needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Carbon County, WY?

Carbon County is in Zone 5a with an average last frost of May 31. Plan your Cumin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carbon County, WY?

Carbon County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 18.

🌱

Your Carbon County Garden Planner — Free

A 24-page printable planner built for Carbon 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 Carbon County, WY. 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.