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When to plant Calendula in Audrain County County,

Audrain County County gardeners should plant Calendula between March 13 and April 3 in spring. With Audrain County County's Zone 6b climate (last frost April 10), Calendula needs 70 days to mature — plant by August 16 for a full harvest.

When to Plant Calendula in Audrain County, MO

Audrain County, Missouri Zone 6b June

June to-do list for Audrain County, Missouri

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Audrain County, Missouri.

Avg. last frost April 10
Avg. first frost October 25
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Harvest calendula as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong July, finish these tasks
  • First harvests: calendula

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Calendula (Calendula officinalis) is a cheerful, edible-flowered cool-season annual valued by herbalists, chefs, and gardeners alike. Its golden-orange petals are used in salves, teas, and as a saffron substitute. Hardy enough to tolerate light frosts, it blooms prolifically in spring and fall, taking a pause during the hottest weeks of summer.

Audrain County, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 25, giving you a growing season of approximately 198 days.

At an elevation of 1,376 feet, Audrain County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Audrain County, MO (Zone 6b) Moderate season
198 days
Last Spring Frost April 10
198 growing days
First Fall Frost October 25
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Audrain County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (49 days to spare)
Start indoors: Feb 21 Transplant: Apr 4 🌸 Bloom: May 23 – Aug 29
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🌸 Bloom: May 29 – Sep 4
Safe Start (90%) ✓ Fits season (50 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🌸 Bloom: Jun 11 – Sep 17

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 Audrain County

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

Soil pH

Your soil pH (5.5–6.6) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Calendula.

How to Plant Calendula

0.3"
Planting Depth
9"
Between Plants
12"
Between Rows

Succession Planting Calendula

4
successive plantings in your 198-day season

Sow every 5.7 weeks. Last sowing by Aug 16 to harvest before frost.

Calendula Water Budget

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

Monthly Watering Guide for Calendula

Calendula needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Calendula Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Calendula 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.

Calendula needs ~825 GDD — county provides 2,722 GDD Excellent fit

Calendula Planting Timeline — Audrain County, MO

Calendula Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 13 Mar 13 – Apr 3
Bloom May 29 May 29 – Sep 4

Plant 0.3" deep · 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

198 days in Audrain County

Growing Tips for Calendula in Audrain County

Direct sow Calendula outdoors after April 10 in Audrain County when soil has warmed and frost danger has passed.

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

General growing tips

Direct-sow in early spring as soon as soil can be worked — seeds germinate in cool soil (50-65°F). In zones 7+, also sow in fall for winter/spring bloom. Deadhead consistently to extend bloom. Plants self-seed readily; save a few spent heads and allow them to drop. Harvest petals when flowers are fully open for best flavor and medicinal value.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Calendula in Audrain County, MO?

Audrain County is in Zone 6b with an average last frost of April 10. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Audrain County, MO?

Audrain County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 25.

When should I plant Calendula in Audrain County County, ?

In Audrain County County, , plant Calendula after the last frost (around April 10) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Audrain County County, for Calendula?

Audrain County County sits in USDA Zone 6b. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.

Can Calendula grow in Audrain County County's climate?

Yes — Calendula grows well in Audrain County County's temperate climate. Audrain County County averages a 198-day frost-free season, with last frost around April 10 and first frost around October 25.

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Your Audrain County Garden Planner — Free

A 22-page printable planner built for Audrain County (Zone 6b). 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 Audrain County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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