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When to Plant Calendula in Washington County, UT

Washington County, Utah Zone 8b June

Your June planting checklist for Washington County, Utah

Your garden in Washington County, Utah is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 14.6 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.

A few tasks this June that'll pay off in 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.

Washington County, Utah is in USDA Zone 8b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 feet, Washington County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Calendula during the growing season. 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
Washington County, UT (Zone 8b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1
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Washington County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Transplant: Feb 20 🌸 Bloom: Apr 10 – Sep 4
Recommended (50%) ✓ Fits season (34 days to spare)
Transplant: Mar 16 🌸 Bloom: May 4 – Sep 28
Safe Start (90%) ✓ Fits season (3 days to spare)
Transplant: May 6 🌸 Bloom: Jun 24 – Nov 18

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 Washington County

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

Soil pH

Your soil pH (6.7–8.0) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Washington 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 (2.4%). 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

4
successive plantings in your 209-day season

Sow every 5.7 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 881 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 2.2" 1.2" 1" 💧 Light watering
May 2.2" 1.4" 0.8" 💧 Light watering
Jun 2.2" 0.9" 1.3" 🚿 Regular watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.4" 0.8" 💧 Light watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 2.2" 1.2" 1" 💧 Light watering
Nov 2.2" 1" 1.2" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Washington 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 ~1,050 GDD — county provides 3,657 GDD Excellent fit

Calendula Planting Timeline — Washington County, UT

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors March 16 Mar 16 – Mar 30
Direct Sow February 16 Feb 16 – Mar 9
Bloom May 4 May 4 – Sep 28
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March Transplant Outdoors Direct Sow
April
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 · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

209 days in Washington County

Growing Tips for Calendula in Washington County

Direct sow Calendula outdoors after April 06 in Washington 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.

Washington 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 Washington County, UT?

Washington County is in Zone 8b with an average last frost of April 6. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, UT?

Washington County, Utah is in USDA Hardiness Zone 8b. The average last spring frost is April 6 and first fall frost is November 1.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 8b). 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 Washington 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.