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When to plant Calendula in Johnson County, KS

Aim to plant Calendula in Johnson County on or after March 11; the window stays open through April 1. Johnson County's 201-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Calendula in Johnson County, KS

Johnson County, Kansas Zone 6b July

Johnson County, Kansas gardeners: here's your July plan

We've pulled the most time-sensitive tasks for Johnson County, Kansas this July and put them front and centre. Tackle them in order.

Avg. last frost April 8
Avg. first frost October 26
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Basket week: calendula

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

Looking ahead to August
  • 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.

Johnson County, Kansas is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.

At an elevation of 768 feet, Johnson County receives approximately 27.6 inches of rainfall annually with predominantly 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
Johnson County, KS (Zone 6b) Long season
201 days
Last Spring Frost April 8
201 growing days
First Fall Frost October 26

Johnson County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Feb 21 Transplant: Apr 4 🌸 Bloom: May 23 – Aug 29
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Feb 25 Transplant: Apr 8 🌸 Bloom: May 27 – Sep 2
Safe Start (90%) ✓ Fits season (58 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 Johnson County

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

Soil pH

Your soil pH (6.8–7.2) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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 201-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
0.6″/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 0.8" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.8" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.3" 0" ✅ Rainfall sufficient
Oct 2.2" 1.8" 0.4" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Johnson 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 3,065 GDD Excellent fit

Calendula Planting Timeline — Johnson County, KS

Calendula Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors April 8 Apr 8 – Apr 22
Direct Sow March 11 Mar 11 – Apr 1
Bloom May 27 May 27 – Sep 2

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

201 days in Johnson County

Growing Tips for Calendula in Johnson County

Direct sow Calendula outdoors after April 08 in Johnson 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 Johnson County, KS?

Johnson County is in Zone 6b with an average last frost of April 8. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, KS?

Johnson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.

When should I plant Calendula in Johnson County, KS?

In Johnson County, KS, plant Calendula after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Johnson County, KS for Calendula?

Johnson 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 Johnson County's climate?

Yes — Calendula grows well in Johnson County's temperate climate. Johnson County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.

🌱

Your Johnson County Garden Planner — Free

A 22-page printable planner built for Johnson 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 Johnson County, KS. Local conditions may vary. Last updated: July 2026.

Sources & credits

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