Blog

When to plant Calendula in Mapaville, MO

In Mapaville, plant Calendula in spring between March 13 and April 3, once soil temps hold above 50°F. Mapaville's last frost averages April 10, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 50–70 days before the first frost on October 26.

When to Plant Calendula in Mapaville, MO

Jefferson County, Missouri Zone 6b June

Jefferson County, Missouri gardeners: here's your June plan

A quick June briefing for Jefferson County, Missouri gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 10
Avg. first frost October 26
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Harvest calendula as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in July — start thinking about
  • First harvests: calendula

Instant PDF download. No spam, unsubscribe any time.

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.

Mapaville, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 26, giving you a growing season of approximately 199 days.

At an elevation of 839 feet, Jefferson County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Mapaville, MO (Zone 6b) Moderate season
199 days
Last Spring Frost April 10
199 growing days
First Fall Frost October 26

Mapaville Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

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 (52 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🌸 Bloom: May 29 – Sep 4
Safe Start (90%) ✓ Fits season (51 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 Mapaville

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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 199-day season

Sow every 5.7 weeks. Last sowing by Aug 17 to harvest before frost.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 3.2" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jefferson 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 ~915 GDD — county provides 3,034 GDD Excellent fit

Calendula Planting Timeline — Mapaville, 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

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

199 days in Jefferson County

Growing Tips for Calendula in Mapaville

Direct sow Calendula outdoors after April 10 in Jefferson 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 →

When should I plant Calendula in Mapaville, MO?

In Mapaville, MO, plant Calendula after the last frost (around April 10) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Mapaville, MO for Calendula?

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

Can Calendula grow in Mapaville's climate?

Yes — Calendula grows well in Mapaville's temperate climate. Mapaville averages a 199-day frost-free season, with last frost around April 10 and first frost around October 26.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson 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.

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 Jefferson County, MO. Local conditions may vary. Last updated: June 2026.