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When to Plant Calendula in Fulton, OH

Morrow County, Ohio Zone 6a June

Your June gardening checklist

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

Avg. last frost April 29
Avg. first frost October 15
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Time to start calendula inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Collect calendula at their peak

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

Before July arrives, get these ready
  • 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.

Fulton, Ohio is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 15, giving you a growing season of approximately 169 days.

At an elevation of 800 feet, Morrow County receives approximately 34.2 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
Fulton, OH (Zone 6a) Moderate season
169 days
Last Spring Frost April 29
169 growing days
First Fall Frost October 15

Fulton Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Mar 15 Transplant: Apr 26 🌸 Bloom: Jun 14 – Sep 13
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jun 17 – Sep 16
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Apr 4 Transplant: May 16 🌸 Bloom: Jul 4 – Oct 3

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 Fulton

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

Soil pH

Your soil pH (6.0–6.8) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Calendula will thrive.

How to Plant Calendula

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

Succession Planting Calendula

3
successive plantings in your 169-day season

Sow every 5.7 weeks. Last sowing by Aug 06 to harvest before frost.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.6" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Morrow 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 2,577 GDD Excellent fit

Calendula Planting Timeline — Fulton, OH

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 1 Apr 1 – Apr 22
Bloom June 17 Jun 17 – Sep 16

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors
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

169 days in Morrow County

Growing Tips for Calendula in Fulton

Direct sow Calendula outdoors after April 29 in Morrow 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 →

🌱

Your Morrow County Garden Planner — Free

A 22-page printable planner built for Morrow 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 Morrow County, OH. Local conditions may vary. Last updated: June 2026.