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When to plant Calendula in Richland County, IL

Richland County's climate puts the Calendula spring window between March 16 and April 6. time plantings around the expected last-frost window for best survival.

When to Plant Calendula in Richland County, IL

Richland County, Illinois Zone 6b June

Your June planting checklist for Richland County, Illinois

June is a pivotal month for Richland County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 13
Avg. first frost October 27
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. It's harvest week for calendula

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

Coming up in July — start thinking about
  • 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.

Richland County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 27, giving you a growing season of approximately 197 days.

At an elevation of 1,135 feet, Richland County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Richland County, IL (Zone 6b) Moderate season
197 days
Last Spring Frost April 13
197 growing days
First Fall Frost October 27

Richland County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Feb 24 Transplant: Apr 7 🌸 Bloom: May 26 – Sep 1
Recommended (50%) ✓ Fits season (50 days to spare)
Start indoors: Mar 2 Transplant: Apr 13 🌸 Bloom: Jun 1 – Sep 7
Safe Start (90%) ✓ Fits season (50 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🌸 Bloom: Jun 15 – Sep 21

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 Richland County

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

Soil pH

Your soil pH (6.2–7.0) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Calendula will thrive.

How to Plant Calendula

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

Succession Planting Calendula

4
successive plantings in your 197-day season

Sow every 5.7 weeks. Last sowing by Aug 18 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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.4" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.8" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 3" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Richland 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 ~1,095 GDD — county provides 3,595 GDD Excellent fit

Calendula Planting Timeline — Richland County, IL

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 16 Mar 16 – Apr 6
Bloom June 1 Jun 1 – Sep 7

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 6b

📆 Growing Season

197 days in Richland County

Growing Tips for Calendula in Richland County

Direct sow Calendula outdoors after April 13 in Richland 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 Richland County, IL?

Richland County is in Zone 6b with an average last frost of April 13. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, IL?

Richland County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 27.

When should I plant Calendula in Richland County, IL?

In Richland County, IL, plant Calendula after the last frost (around April 13) and before the first frost (around October 27). Best results when soil holds above 50°F.

What growing zone is Richland County, IL for Calendula?

Richland 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 Richland County's climate?

Yes — Calendula grows well in Richland County's temperate climate. Richland County averages a 197-day frost-free season, with last frost around April 13 and first frost around October 27.

🌱

Your Richland County Garden Planner — Free

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.