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When to Plant Cumin in Grant County, OR

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.

Grant County, Oregon is in USDA Zone 5b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.

At an elevation of 2,838 feet, Grant County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Cumin to ensure they mature before fall.

Grant County, OR (Zone 5b) Very short season
96 days
Last Spring Frost June 6
96 growing days
First Fall Frost September 10

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 15 Transplant: May 13 🍅 Harvest: Aug 26 – Oct 28
Recommended (50%) ✗ May not fit
Start indoors: May 2 Transplant: May 30 🍅 Harvest: Sep 12 – Nov 14
Safe Start (90%) ✗ May not fit
Start indoors: May 22 Transplant: Jun 19 🍅 Harvest: Oct 2 – Dec 4

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 Grant County

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

Soil pH

Your soil pH (5.4โ€“6.4) is more acidic than Cumin prefers (6.0โ€“8.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Grant County is excellent for Cumin โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Cumin.

Organic Matter

Organic matter is excellent (4.8%) โ€” Cumin will thrive.

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 2.9" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr โ€” 1.5" 0" โ„๏ธ Dormant
May โ€” 1.3" 0" โ„๏ธ Dormant
Jun 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Jul 2.2" 0.4" 1.8" ๐Ÿšฟ Regular watering
Aug 2.2" 0.4" 1.8" ๐Ÿšฟ Regular watering
Sep 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Oct โ€” 1.8" 0" โ„๏ธ Dormant
Nov โ€” 3.1" 0" โ„๏ธ Dormant
Dec โ€” 3.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Grant County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,348 GDD — county provides 1,176 GDD May not mature

Cumin Planting Timeline โ€” Grant County, OR

Cumin Planting Calendar

Activity When Date Range
Start Indoors May 2 May 2 โ€“ May 16
Transplant Outdoors May 30 May 30 โ€“ Jun 13
Direct Sow May 23 May 23 โ€“ Jun 13
Harvest September 12 Sep 12 โ€“ Nov 14
Fall Sowing July 2 Jul 2 โ€“ Jul 16

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

100โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

96 days in Grant County

Growing Tips for Cumin in Grant County

Direct sow Cumin outdoors after June 06 in Grant County when soil has warmed and frost danger has passed.

Your 96.0-day growing season in Grant 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.

Grant County receives only 23" of rain annually. Cumin needs consistent moisture โ€” 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 Grant County, OR?

Grant County is in Zone 5b with an average last frost of June 6. Plan your Cumin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, OR?

Grant County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is June 6 and first fall frost is September 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grant County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Grant County, OR. Local conditions may vary. Last updated: April 2026.