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When to Plant Calendula in Rogers County, OK

Rogers County, Oklahoma Zone 7a June

Rogers County, Oklahoma gardeners: here's your June plan

Here's what deserves your attention in Rogers County, Oklahoma this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 7
Avg. first frost October 26
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Harvest calendula as they ripen

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

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.

Rogers County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 505 feet, Rogers County receives approximately 30.8 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Rogers County, OK (Zone 7a) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26
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Rogers 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 (46 days to spare)
Start indoors: Feb 19 Transplant: Apr 2 🌸 Bloom: May 21 – Sep 3
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Feb 24 Transplant: Apr 7 🌸 Bloom: May 26 – Sep 8
Safe Start (90%) ✓ Fits season (48 days to spare)
Start indoors: Mar 13 Transplant: Apr 24 🌸 Bloom: Jun 12 – Sep 25

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 Rogers 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 Rogers County is excellent for Calendula — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Calendula.

Organic Matter

Organic matter is excellent (4.1%) — Calendula will thrive.

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

4
successive plantings in your 202-day season

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

For a dedicated fall crop, sow by Aug 31.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 17 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 0.8" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 5.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 4.2" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.1" 0.1" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Rogers 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 ~1,140 GDD — county provides 3,838 GDD Excellent fit

Calendula Planting Timeline — Rogers County, OK

Calendula Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 3 Mar 3 – Mar 24
Bloom May 26 May 26 – Sep 8
Fall Sowing August 31 Aug 31 – Sep 14

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
May Bloom
June Bloom
July Bloom
August Fall Sowing 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 7a

📆 Growing Season

202 days in Rogers County

Growing Tips for Calendula in Rogers County

Direct sow Calendula outdoors after April 07 in Rogers 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 Rogers County, OK?

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

What planting zone is Rogers County, OK?

Rogers County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 26.

🌱

Your Rogers County Garden Planner — Free

A 22-page printable planner built for Rogers County (Zone 7a). 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 Rogers 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.