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When to plant Cumin in Angwin, CA

Plant Cumin in Angwin from February 5 to February 26 in spring. Angwin sits in USDA Zone 9b, with last frost around February 26 and first frost on November 26. A second sowing from October 1 to October 15 extends the harvest into fall.

When to Plant Cumin in Angwin, CA

Napa County, California Zone 9b August

This month in Napa County, California

Welcome to August in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 26
Avg. first frost November 26
Soil temp (4") 95°F
Watering Critical
Pest pressure High
Daylight 13.5 hrs
  1. Harvest cumin as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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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.

Angwin, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Cumin during the growing season.

Angwin, CA (Zone 9b) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Angwin Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Cumin Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Jan 13 Transplant: Feb 3 🍅 Harvest: May 19 – Jul 21
Recommended (50%) ✓ Fits season (112 days to spare)
Start indoors: Jan 29 Transplant: Feb 19 🍅 Harvest: Jun 4 – Aug 6
Safe Start (90%) ✓ Fits season (98 days to spare)
Start indoors: Mar 5 Transplant: Mar 26 🍅 Harvest: Jul 9 – Sep 10

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 Angwin

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

Soil pH

Your soil pH (6.7–7.5) is within Cumin's preferred range (6.0–8.0).

Soil Texture

The loam soil in Napa 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 (3.0%). Annual compost additions will help Cumin.

How to Plant Cumin

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

Fall planting: Sow 8 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
0.1″/week
Watering frequency Only during dry spells
Season total 332 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 7.5" 0" ❄️ Dormant
Feb 2.2" 7.8" 0" ✅ Rainfall sufficient
Mar 2.2" 5.8" 0" ✅ Rainfall sufficient
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 0.8" 1.4" 🚿 Regular watering
Jun 2.2" 0.2" 2" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.3" 1.9" 🚿 Regular watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 2.2" 3.3" 0" ✅ Rainfall sufficient
Dec 5.6" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Napa 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 4,384 GDD Excellent fit

Cumin Planting Timeline — Angwin, CA

Cumin Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors February 19 Feb 19 – Mar 5
Direct Sow February 5 Feb 5 – Feb 26
Harvest June 4 Jun 4 – Aug 6
Fall Sowing October 1 Oct 1 – Oct 15

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9b

📆 Growing Season

273 days in Napa County

Growing Tips for Cumin in Angwin

Direct sow Cumin outdoors after February 26 in Napa 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.

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 →

When should I plant Cumin in Angwin, CA?

In Angwin, CA, plant Cumin after the last frost (around February 26) and before the first frost (around November 26). Best results when soil holds above 50°F.

What growing zone is Angwin, CA for Cumin?

Angwin sits in USDA Zone 9b. Cumin grows reliably in zones 5a through 11b, so it's a good fit here.

Can Cumin grow in Angwin's climate?

Yes — Cumin grows well in Angwin's temperate climate. Angwin averages a 274-day frost-free season, with last frost around February 26 and first frost around November 26.

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Your Napa County Garden Planner — Free

A 22-page printable planner built for Napa County (Zone 9b). 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 Napa County, CA. Local conditions may vary. Last updated: August 2026.