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When to Plant Cumin in Boardman, OR

Morrow County, Oregon Zone 7b August

This month in Morrow County, Oregon

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

Avg. last frost April 25
Avg. first frost October 15
Soil temp (4") 77°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. Bring in the cumin

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

  2. Start your fall crops: cumin

    Mid-season soil is hot. Sow a bit deeper than the packet suggests to find cooler, damper ground.

Get ahead of September
  • First harvests: 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.

Boardman, Oregon is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 15, giving you a growing season of approximately 173 days.

At an elevation of 2,335 feet, Morrow County receives approximately 20.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cumin during the growing season.

Boardman, OR (Zone 7b) Moderate season
173 days
Last Spring Frost April 25
173 growing days
First Fall Frost October 15

Boardman Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Cumin Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jul 21 – Sep 22
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: Aug 1 – Oct 3
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Aug 19 – Oct 21

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 Boardman

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Cumin's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cumin.

Organic Matter

Organic matter is excellent (4.6%) — 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.

Cumin Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 263 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 3" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 1.4" 0.8" 💧 Light watering
May 2.2" 1.2" 1" 💧 Light watering
Jun 2.2" 0.7" 1.5" 🚿 Regular watering
Jul 2.2" 0.4" 1.8" 🚿 Regular watering
Aug 2.2" 0.4" 1.8" 🚿 Regular watering
Sep 2.2" 0.8" 1.4" 🚿 Regular watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Morrow 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 ~1,760 GDD — county provides 2,768 GDD Excellent fit

Cumin Planting Timeline — Boardman, OR

Cumin Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 11 Apr 11 – May 2
Harvest August 1 Aug 1 – Oct 3
Fall Sowing August 6 Aug 6 – Aug 20

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July
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 7b

📆 Growing Season

173 days in Morrow County

Growing Tips for Cumin in Boardman

Direct sow Cumin outdoors after April 25 in Morrow 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.

Morrow County receives only 21" 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 →

🌱

Your Morrow County Garden Planner — Free

A 22-page printable planner built for Morrow County (Zone 7b). 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 Morrow County, OR. Local conditions may vary. Last updated: August 2026.