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When to Plant Chamomile in Custer County, MT

Custer County, Montana Zone 4b May

Custer County, Montana gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Custer County, Montana this May and put them front and centre. Tackle them in order.

Avg. last frost May 14
Avg. first frost September 27
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Time to transplant chamomile

    Frost risk is low now in Custer County, Montana. If you've been covering beds overnight, you can stop.

  2. Sow chamomile where they'll grow

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

June prep starts now
  • Starting indoors: 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.

Custer County, Montana is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 27, giving you a growing season of approximately 136 days.

At an elevation of 5,983 feet, Custer County receives approximately 24 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.

Custer County, MT (Zone 4b) Short season
136 days
Last Spring Frost May 14
136 growing days
First Fall Frost September 27

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jul 5 – Sep 13
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 9 – Sep 17
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jul 20 – Sep 28

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 Custer County

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

Soil pH

Your soil pH (6.5–8.1) overlaps with Chamomile's range (5.6–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Chamomile.

How to Plant Chamomile

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Chamomile

2
successive plantings in your 136-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 05.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.7″/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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 1.7" 2.6" 0" ✅ Rainfall sufficient
Jun 1.7" 1.4" 0.3" 💧 Light watering
Jul 1.7" 2.2" 0" ✅ Rainfall sufficient
Aug 1.7" 2.3" 0" ✅ Rainfall sufficient
Sep 1.7" 2.1" 0" ✅ Rainfall sufficient
Oct 1.9" 0" ❄️ Dormant
Nov 1.9" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Custer 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 1,360 GDD Excellent fit

Chamomile Planting Timeline — Custer County, MT

Chamomile Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Harvest July 9 Jul 9 – Sep 17
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Harvest
September Harvest
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 4b

📆 Growing Season

136 days in Custer County

Growing Tips for Chamomile in Custer County

Direct sow Chamomile outdoors after May 14 in Custer 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 Custer County, MT?

Custer County is in Zone 4b with an average last frost of May 14. Plan your Chamomile planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, MT?

Custer County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 27.

🌱

Your Custer County Garden Planner — Free

A 24-page printable planner built for Custer County (Zone 4b). 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 Custer 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.