Blog

When to Plant Chamomile in Yellowstone County, MT

Yellowstone County, Montana Zone 5a May

May in the garden — Yellowstone County, Montana

Each item below is timed to Yellowstone County, Montana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 9
Avg. first frost October 3
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 14.7 hrs
  1. Get chamomile in the ground

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

To set up a strong June, finish these tasks
  • Starting indoors: chamomile

Instant PDF download. No spam, unsubscribe any time.

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.

Yellowstone County, Montana is in USDA Zone 5a. The average last spring frost is May 9 and the first fall frost is October 3, giving you a growing season of approximately 147 days.

At an elevation of 7,432 feet, Yellowstone County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Chamomile to ensure they mature before fall.

Yellowstone County, MT (Zone 5a) Short season
147 days
Last Spring Frost May 9
147 growing days
First Fall Frost October 3
Share this guide:

Yellowstone County Soil Profile

Soil Type

Loam

Soil pH

6.2-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🍅 Harvest: Jun 29 – Sep 7
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Apr 4 Transplant: May 2 🍅 Harvest: Jul 4 – Sep 12
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Apr 17 Transplant: May 15 🍅 Harvest: Jul 17 – Sep 25

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 Yellowstone County

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

Soil pH

Your soil pH (6.2–8.0) overlaps with Chamomile's range (5.6–7.5), though not a perfect match.

Soil Texture

The loam soil in Yellowstone 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 (2.4%). Annual compost additions will help Chamomile.

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

2
successive plantings in your 147-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 25.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.3" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.9" 0" ❄️ Dormant
May 1.7" 2.7" 0" ✅ Rainfall sufficient
Jun 1.7" 1.7" 0" ✅ Rainfall sufficient
Jul 1.7" 1.7" 0" ✅ Rainfall sufficient
Aug 1.7" 2.5" 0" ✅ Rainfall sufficient
Sep 1.7" 1.7" 0" ✅ Rainfall sufficient
Oct 1.7" 1.8" 0" ✅ Rainfall sufficient
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Yellowstone 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 ~750 GDD — county provides 1,470 GDD Excellent fit

Chamomile Planting Timeline — Yellowstone County, MT

Chamomile Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest July 4 Jul 4 – Sep 12
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

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

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 5a

📆 Growing Season

147 days in Yellowstone County

Growing Tips for Chamomile in Yellowstone County

Direct sow Chamomile outdoors after May 09 in Yellowstone 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 Yellowstone County, MT?

Yellowstone County is in Zone 5a with an average last frost of May 9. Plan your Chamomile planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yellowstone County, MT?

Yellowstone County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 9 and first fall frost is October 3.

🌱

Your Yellowstone County Garden Planner — Free

A 24-page printable planner built for Yellowstone County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Yellowstone County, MT. 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.