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When to Plant Chamomile in Shelby County, IA

Shelby County, Iowa Zone 5a May

Your May game plan for Shelby County, Iowa

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 30
Avg. first frost October 3
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
Coming up in June — start thinking about
  • Starting indoors: chamomile
  • 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.

Shelby County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 3, giving you a growing season of approximately 156 days.

At an elevation of 1,113 feet, Shelby County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Chamomile during the growing season.

Shelby County, IA (Zone 5a) Moderate season
156 days
Last Spring Frost April 30
156 growing days
First Fall Frost October 3

Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 27
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Apr 10 Transplant: May 8 🍅 Harvest: Jul 10 – Sep 18

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 Shelby County

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

Soil pH

Your soil pH (6.2–7.0) is within Chamomile's preferred range (5.6–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — 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 156-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
0.8″/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 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 1.7" 2.8" 0" ✅ Rainfall sufficient
May 1.7" 3.7" 0" ✅ Rainfall sufficient
Jun 1.7" 3.8" 0" ✅ Rainfall sufficient
Jul 1.7" 3.5" 0" ✅ Rainfall sufficient
Aug 1.7" 2.9" 0" ✅ Rainfall sufficient
Sep 1.7" 2.8" 0" ✅ Rainfall sufficient
Oct 1.7" 2.5" 0" ✅ Rainfall sufficient
Nov 2" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Shelby 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 ~1,088 GDD — county provides 2,262 GDD Excellent fit

Chamomile Planting Timeline — Shelby County, IA

Chamomile Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest June 25 Jun 25 – Sep 3
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 Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing 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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

156 days in Shelby County

Growing Tips for Chamomile in Shelby County

Direct sow Chamomile outdoors after April 30 in Shelby 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 Shelby County, IA?

Shelby County is in Zone 5a with an average last frost of April 30. Plan your Chamomile planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, IA?

Shelby County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 3.

🌱

Your Shelby County Garden Planner — Free

A 24-page printable planner built for Shelby 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.

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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 Shelby County, IA. 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.