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When to Plant Chamomile in Colusa County, CA

Colusa County, California Zone 9b May

This month in Colusa County, California

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Colusa County, California.

Avg. last frost March 6
Avg. first frost November 28
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. It's harvest week for chamomile

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • First harvests: chamomile

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Chamomile is a daisy-like herb famous for its calming, apple-scented tea. German chamomile is an annual while Roman chamomile is a perennial ground cover.

Colusa County, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 112 feet, Colusa County receives approximately 29.8 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Chamomile during the growing season.

Colusa County, CA (Zone 9b) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Colusa County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Jan 26 Transplant: Feb 16 🍅 Harvest: Apr 20 – Jun 29
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Feb 6 Transplant: Feb 27 🍅 Harvest: May 1 – Jul 10
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Mar 21 Transplant: Apr 11 🍅 Harvest: Jun 13 – Aug 22

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 Colusa County

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

Soil pH

Your soil pH (6.6–7.5) is within Chamomile's preferred range (5.6–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Chamomile.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Chamomile.

How to Plant Chamomile

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Chamomile

5
successive plantings in your 267-day season

Sow every 6.9 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Oct 03.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 146 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Chamomile

Chamomile needs approximately 0.4 inches of water per week (1.7" per month). Here's how your county's rainfall compares month by month.

Month Chamomile Needs Rainfall You Supplement Action
Jan 6.2" 0" ❄️ Dormant
Feb 6.7" 0" ❄️ Dormant
Mar 1.7" 4.7" 0" ✅ Rainfall sufficient
Apr 1.7" 2" 0" ✅ Rainfall sufficient
May 1.7" 0.7" 1" 🚿 Regular watering
Jun 1.7" 0.1" 1.6" 🚿 Regular watering
Jul 1.7" 0" 1.7" 🚿 Regular watering
Aug 1.7" 0" 1.7" 🚿 Regular watering
Sep 1.7" 0.3" 1.4" 🚿 Regular watering
Oct 1.7" 1.1" 0.6" 💧 Light watering
Nov 1.7" 3" 0" ✅ Rainfall sufficient
Dec 4.9" 0" ❄️ Dormant

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

Chamomile 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.

Chamomile needs ~1,538 GDD — county provides 5,473 GDD Excellent fit

Chamomile Planting Timeline — Colusa County, CA

Chamomile Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors February 27 Feb 27 – Mar 13
Direct Sow February 13 Feb 13 – Mar 6
Harvest May 1 May 1 – Jul 10
Fall Sowing October 3 Oct 3 – Oct 17

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.4"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

267 days in Colusa County

Growing Tips for Chamomile in Colusa County

Direct sow Chamomile outdoors after March 06 in Colusa County when soil has warmed and frost danger has passed.

Common pests for Chamomile in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow on the soil surface as seeds need light. Harvest flowers when petals begin to curl back. Chamomile self-sows freely and improves the health of nearby plants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chamomile in Colusa County, CA?

Colusa County is in Zone 9b with an average last frost of March 6. Plan your Chamomile planting based on this frost date — see the calendar above for exact timing.

What planting zone is Colusa County, CA?

Colusa County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 6 and first fall frost is November 28.

🌱

Your Colusa County Garden Planner — Free

A 24-page printable planner built for Colusa 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 Colusa County, CA. 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.