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When to Plant Calendula in Marshall County, OK

Marshall County, Oklahoma Zone 8a June

Top priorities for Marshall County, Oklahoma gardeners in June

Here's what deserves your attention in Marshall County, Oklahoma this month. Everything below is tailored to Zone 8a and timed around your local frost dates.

Avg. last frost March 24
Avg. first frost November 12
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs
  1. Pick calendula

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

Get ahead of July
  • 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.

Marshall County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.

At an elevation of 520 feet, Marshall County receives approximately 23.7 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
Marshall County, OK (Zone 8a) Long season
233 days
Last Spring Frost March 24
233 growing days
First Fall Frost November 12

Marshall County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Transplant: Feb 25 🌸 Bloom: Apr 15 – Aug 26
Recommended (50%) ✓ Fits season (65 days to spare)
Transplant: Mar 10 🌸 Bloom: Apr 28 – Sep 8
Safe Start (90%) ✓ Fits season (62 days to spare)
Transplant: Mar 31 🌸 Bloom: May 19 – Sep 29

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 Marshall County

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

Soil pH

Your soil pH (6.2–7.8) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Calendula.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Calendula.

How to Plant Calendula

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Calendula

5
successive plantings in your 233-day season

Sow every 5.7 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 554 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 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 2.2" 1.6" 0.6" 💧 Light watering
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 3.4" 0" ✅ Rainfall sufficient
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 2.8" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 2.2" 0.9" 1.3" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Marshall 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 4,427 GDD Excellent fit

Calendula Planting Timeline — Marshall County, OK

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors March 10 Mar 10 – Mar 24
Direct Sow February 10 Feb 10 – Mar 3
Bloom April 28 Apr 28 – Sep 8
Fall Sowing September 3 Sep 3 – Sep 17

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

233 days in Marshall County

Growing Tips for Calendula in Marshall County

Direct sow Calendula outdoors after March 24 in Marshall 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.

Marshall County receives only 24" 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 Marshall County, OK?

Marshall County is in Zone 8a with an average last frost of March 24. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, OK?

Marshall County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 12.

🌱

Your Marshall County Garden Planner — Free

A 22-page printable planner built for Marshall County (Zone 8a). 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 Marshall 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.