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When to Plant Chamomile in Columbia County, OR

Columbia County, Oregon Zone 8b May

Top priorities for Columbia County, Oregon gardeners in May

A quick May briefing for Columbia County, Oregon gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 14
Avg. first frost October 29
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
  1. Start chamomile under lights

    Label every cell. You will absolutely forget which is which otherwise.

A few tasks this May that'll pay off in 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.

Columbia County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 29, giving you a growing season of approximately 198 days.

At an elevation of 396 feet, Columbia County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Chamomile during the growing season.

Columbia County, OR (Zone 8b) Moderate season
198 days
Last Spring Frost April 14
198 growing days
First Fall Frost October 29

Columbia County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Mar 3 Transplant: Mar 31 🍅 Harvest: Jun 2 – Aug 11
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 9 – Aug 18
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Apr 5 Transplant: May 3 🍅 Harvest: Jul 5 – Sep 13

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 Columbia County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Chamomile's range (5.6–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Chamomile will thrive.

How to Plant Chamomile

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Chamomile

3
successive plantings in your 198-day season

Sow every 6.9 weeks. Last sowing by Jul 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 20.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 6.5" 0" ❄️ Dormant
Feb 4.8" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 1.7" 3.2" 0" ✅ Rainfall sufficient
May 1.7" 2.9" 0" ✅ Rainfall sufficient
Jun 1.7" 1.7" 0" ✅ Rainfall sufficient
Jul 1.7" 0.7" 1" 🚿 Regular watering
Aug 1.7" 0.8" 0.9" 🚿 Regular watering
Sep 1.7" 1.9" 0" ✅ Rainfall sufficient
Oct 1.7" 3.9" 0" ✅ Rainfall sufficient
Nov 7.6" 0" ❄️ Dormant
Dec 7.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Columbia 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 ~1,031 GDD — county provides 2,722 GDD Excellent fit

Chamomile Planting Timeline — Columbia County, OR

Chamomile Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 31 Mar 31 – Apr 21
Harvest June 9 Jun 9 – Aug 18
Fall Sowing August 20 Aug 20 – Sep 3

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.4"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

198 days in Columbia County

Growing Tips for Chamomile in Columbia County

Direct sow Chamomile outdoors after April 14 in Columbia 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 Columbia County, OR?

Columbia County is in Zone 8b with an average last frost of April 14. Plan your Chamomile planting based on this frost date — see the calendar above for exact timing.

What planting zone is Columbia County, OR?

Columbia County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 29.

🌱

Your Columbia County Garden Planner — Free

A 24-page printable planner built for Columbia County (Zone 8b). 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 Columbia County, OR. 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.