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When to Plant Calendula in McClain County, OK

McClain County, Oklahoma Zone 7b June

Your June game plan for McClain County, Oklahoma

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 2
Avg. first frost November 5
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Basket week: calendula

    If you can't use it all right away, check the food-preservation section of your planner.

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.

McClain County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 5, giving you a growing season of approximately 217 days.

At an elevation of 558 feet, McClain County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
McClain County, OK (Zone 7b) Long season
217 days
Last Spring Frost April 2
217 growing days
First Fall Frost November 5
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McClain County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Feb 7 Transplant: Mar 21 🌸 Bloom: May 9 – Sep 5
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Feb 19 Transplant: Apr 2 🌸 Bloom: May 21 – Sep 17
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🌸 Bloom: Jun 3 – Sep 30

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 McClain County

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

Soil pH

Your soil pH (6.4–7.8) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Calendula.

How to Plant Calendula

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Calendula

5
successive plantings in your 217-day season

Sow every 5.7 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Sep 10.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 109 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 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 3" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 2.9" 0" ✅ Rainfall sufficient
Aug 2.2" 3.1" 0" ✅ Rainfall sufficient
Sep 2.2" 2.3" 0" ✅ Rainfall sufficient
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 2.2" 0.9" 1.3" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in McClain 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 ~1,230 GDD — county provides 4,448 GDD Excellent fit

Calendula Planting Timeline — McClain County, OK

Calendula Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow February 26 Feb 26 – Mar 19
Bloom May 21 May 21 – Sep 17
Fall Sowing September 10 Sep 10 – Sep 24

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

217 days in McClain County

Growing Tips for Calendula in McClain County

Direct sow Calendula outdoors after April 02 in McClain 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.

McClain County receives only 23" of rain annually. Calendula needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 McClain County, OK?

McClain County is in Zone 7b with an average last frost of April 2. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is McClain County, OK?

McClain County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 5.

🌱

Your McClain County Garden Planner — Free

A 22-page printable planner built for McClain County (Zone 7b). 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 McClain County, OK. 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.