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When to plant Calendula in Randolph County County,

For Randolph County County, gardeners: plant Calendula March 18 through April 8 once soil reads 50°F.

When to Plant Calendula in Randolph County, MO

Randolph County, Missouri Zone 6a June

This month in Randolph County, Missouri

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

Avg. last frost April 15
Avg. first frost October 18
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Pick calendula

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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  • 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.

Randolph County, Missouri is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.

At an elevation of 1,243 feet, Randolph County receives approximately 33.4 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
Randolph County, MO (Zone 6a) Moderate season
186 days
Last Spring Frost April 15
186 growing days
First Fall Frost October 18

Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🌸 Bloom: May 29 – Aug 28
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🌸 Bloom: Jun 3 – Sep 2
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jun 17 – Sep 16

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 Randolph County

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

Soil pH

Your soil pH (5.7–6.9) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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 186-day season

Sow every 5.7 weeks. Last sowing by Aug 09 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
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.1" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Randolph 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 2,557 GDD Excellent fit

Calendula Planting Timeline — Randolph County, MO

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow March 18 Mar 18 – Apr 8
Bloom June 3 Jun 3 – Sep 2

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

Month-by-Month Timeline

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

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 6a

📆 Growing Season

186 days in Randolph County

Growing Tips for Calendula in Randolph County

Direct sow Calendula outdoors after April 15 in Randolph 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 Randolph County, MO?

Randolph County is in Zone 6a with an average last frost of April 15. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, MO?

Randolph County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 18.

When should I plant Calendula in Randolph County County, ?

In Randolph County County, , plant Calendula after the last frost (around April 15) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Randolph County County, for Calendula?

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

Can Calendula grow in Randolph County County's climate?

Yes — Calendula grows well in Randolph County County's temperate climate. Randolph County County averages a 186-day frost-free season, with last frost around April 15 and first frost around October 18.

🌱

Your Randolph County Garden Planner — Free

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

Sources & credits

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