Blog

When to Plant Calendula in Duchesne County, UT

Duchesne County, Utah Zone 6a June

What to do in June

We've pulled the most time-sensitive tasks for Duchesne County, Utah this June and put them front and centre. Tackle them in order.

Avg. last frost May 10
Avg. first frost October 4
Soil temp (4") 49°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
  1. Fire up the seed-starting tray: calendula

    Label every cell. You will absolutely forget which is which otherwise.

  2. Basket week: calendula

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

July will be here before you know it — start on
  • First harvests: calendula

Instant PDF download. No spam, unsubscribe any time.

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.

Duchesne County, Utah is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 5,302 feet, Duchesne County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Calendula to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Calendula successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Duchesne County, UT (Zone 6a) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4
Share this guide:

Duchesne County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Mar 20 Transplant: May 1 🌸 Bloom: Jun 19 – Sep 18
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Mar 29 Transplant: May 10 🌸 Bloom: Jun 28 – Sep 27
Safe Start (90%) ✗ May not fit
Start indoors: Apr 23 Transplant: Jun 4 🌸 Bloom: Jul 23 – Oct 22

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 Duchesne County

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

Soil pH

Your soil pH (6.4–8.2) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Duchesne 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

3
successive plantings in your 147-day season

Sow every 5.7 weeks. Last sowing by Jul 26 to harvest before frost.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 202 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 0.9" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 2.2" 1.3" 0.9" 💧 Light watering
Jun 2.2" 0.8" 1.4" 🚿 Regular watering
Jul 2.2" 1.3" 0.9" 💧 Light watering
Aug 2.2" 1.3" 0.9" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Duchesne 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 ~600 GDD — county provides 1,470 GDD Excellent fit

Calendula Planting Timeline — Duchesne County, UT

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 12 Apr 12 – May 3
Bloom June 28 Jun 28 – Sep 27

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December
Share this guide:

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 6a

📆 Growing Season

147 days in Duchesne County

Growing Tips for Calendula in Duchesne County

Direct sow Calendula outdoors after May 10 in Duchesne 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.

Duchesne County receives only 13" 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 Duchesne County, UT?

Duchesne County is in Zone 6a with an average last frost of May 10. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Duchesne County, UT?

Duchesne County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 4.

🌱

Your Duchesne County Garden Planner — Free

A 22-page printable planner built for Duchesne 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Duchesne County, UT. 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.