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When to Plant Cumin in Blaine County, ID

Blaine County, Idaho Zone 5b May

Top priorities for Blaine County, Idaho gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 18
Avg. first frost October 3
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
  1. Set out cumin seedlings

    Your last frost (May 18) has passed. These warm-season crops can handle outdoor soil now.

  2. Outdoor sowing time: cumin

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

To set up a strong June, finish these tasks
  • Starting indoors: cumin

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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.

Blaine County, Idaho is in USDA Zone 5b. The average last spring frost is May 18 and the first fall frost is October 3, giving you a growing season of approximately 138 days.

At an elevation of 7,128 feet, Blaine County receives approximately 17.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°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.

Blaine County, ID (Zone 5b) Short season
138 days
Last Spring Frost May 18
138 growing days
First Fall Frost October 3

Blaine County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: Apr 29 🍅 Harvest: Aug 12 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Apr 13 Transplant: May 11 🍅 Harvest: Aug 24 – Oct 26
Safe Start (90%) ✗ May not fit
Start indoors: May 7 Transplant: Jun 4 🍅 Harvest: Sep 17 – Nov 19

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 Blaine County

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

Soil pH

Your soil pH (6.7–8.4) overlaps with Cumin's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cumin.

Organic Matter

Organic matter is moderate (2.2%). 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
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 164 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 1.4" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 2.2" 1.9" 0.3" 💧 Light watering
Jun 2.2" 1.2" 1" 💧 Light watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2.2" 0" ✅ Rainfall sufficient
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Blaine 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 ~1,430 GDD — county provides 1,794 GDD Good fit

Cumin Planting Timeline — Blaine County, ID

Cumin Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest August 24 Aug 24 – Oct 26
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
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

0.5"/week · Only during dry spells

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

138 days in Blaine County

Growing Tips for Cumin in Blaine County

Direct sow Cumin outdoors after May 18 in Blaine County when soil has warmed and frost danger has passed.

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

Blaine County receives only 18" 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 Blaine County, ID?

Blaine County is in Zone 5b with an average last frost of May 18. Plan your Cumin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Blaine County, ID?

Blaine County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 18 and first fall frost is October 3.

🌱

Your Blaine County Garden Planner — Free

A 24-page printable planner built for Blaine 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 Blaine County, ID. 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.