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When to plant Calendula in Holt County County,

For Holt County County, gardeners: plant Calendula March 24 through April 14 once soil reads 50°F.

When to Plant Calendula in Holt County, MO

Holt County, Missouri Zone 6a June

Top priorities for Holt County, Missouri gardeners in June

Your Holt County, Missouri garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 21
Avg. first frost October 15
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Start calendula under lights

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. 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.

To set up a strong July, finish these tasks
  • 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.

Holt County, Missouri is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 15, giving you a growing season of approximately 177 days.

At an elevation of 819 feet, Holt County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Calendula to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Holt County, MO (Zone 6a) Moderate season
177 days
Last Spring Frost April 21
177 growing days
First Fall Frost October 15

Holt County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Mar 3 Transplant: Apr 14 🌸 Bloom: Jun 2 – Sep 1
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Mar 10 Transplant: Apr 21 🌸 Bloom: Jun 9 – Sep 8
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Mar 22 Transplant: May 3 🌸 Bloom: Jun 21 – Sep 20

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 Holt County

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

Soil pH

Your soil pH (5.5–7.1) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Calendula.

How to Plant Calendula

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

Succession Planting Calendula

4
successive plantings in your 177-day season

Sow every 5.7 weeks. Last sowing by Aug 06 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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.4" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 3.1" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Holt 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 ~780 GDD — county provides 2,301 GDD Excellent fit

Calendula Planting Timeline — Holt County, MO

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow March 24 Mar 24 – Apr 14
Bloom June 9 Jun 9 – Sep 8

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 Transplant Outdoors
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 6a

📆 Growing Season

177 days in Holt County

Growing Tips for Calendula in Holt County

Direct sow Calendula outdoors after April 21 in Holt 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 Holt County, MO?

Holt County is in Zone 6a with an average last frost of April 21. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Holt County, MO?

Holt County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 15.

When should I plant Calendula in Holt County County, ?

In Holt County County, , plant Calendula after the last frost (around April 21) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Holt County County, for Calendula?

Holt County County sits in USDA Zone 6a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.

Can Calendula grow in Holt County County's climate?

Yes — Calendula grows well in Holt County County's temperate climate. Holt County County averages a 177-day frost-free season, with last frost around April 21 and first frost around October 15.

🌱

Your Holt County Garden Planner — Free

A 22-page printable planner built for Holt County (Zone 6a). 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 Holt County, MO. 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.