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When to plant Calendula in Pinal County, AZ

Plant Calendula in Pinal County, when soil hits 50°F — usually December 29. Continue planting through January 19 for the spring crop. A second sowing from September 4 to September 18 extends the harvest into fall.

When to Plant Calendula in Pinal County, AZ

Pinal County, Arizona Zone 9a June

Your June game plan for Pinal County, Arizona

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

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 75°F
Watering Critical
Pest pressure High
Daylight 14.2 hrs
  1. Collect calendula at their peak

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

Looking ahead to 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.

Pinal County, Arizona is in USDA Zone 9a. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.

At an elevation of 3,959 feet, Pinal County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°F, so Calendula may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Calendula will need more frequent watering and organic matter to retain nutrients. 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
Pinal County, AZ (Zone 9a) Year-round
277 days
Last Spring Frost February 23
277 growing days
First Fall Frost November 27

Pinal County Soil Profile

Soil Type

Sandy Loam

Soil pH

7-8.6

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (145 days to spare)
Transplant: Jan 13 🌸 Bloom: Feb 24 – Jun 30
Recommended (50%) ✓ Fits season (137 days to spare)
Transplant: Jan 26 🌸 Bloom: Mar 9 – Jul 13
Safe Start (90%) ✓ Fits season (125 days to spare)
Transplant: Feb 24 🌸 Bloom: Apr 7 – Aug 11

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 Pinal County

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

Soil pH

Your soil pH (7.0–8.6) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Pinal County warms quickly in spring but drains fast. Calendula will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Calendula.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Calendula.

How to Plant Calendula

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Calendula

6
successive plantings in your 277-day season

Sow every 5.7 weeks. Last sowing by Sep 18 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,221 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 2.2" 1" 1.2" 🚿 Regular watering
Mar 2.2" 0.8" 1.4" 🚿 Regular watering
Apr 2.2" 0.5" 1.7" 🚿 Regular watering
May 2.2" 0.3" 1.9" 🚿 Regular watering
Jun 2.2" 0.5" 1.7" 🚿 Regular watering
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 1.9" 0.3" 💧 Light watering
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 2.2" 0.8" 1.4" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Pinal 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 ~1,410 GDD — county provides 6,533 GDD Excellent fit

Calendula Planting Timeline — Pinal County, AZ

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors January 26 Jan 26 – Feb 9
Direct Sow December 29 Dec 29 – Jan 19
Bloom March 9 Mar 9 – Jul 13
Fall Sowing September 4 Sep 4 – Sep 18

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

Month-by-Month Timeline

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

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 9a

📆 Growing Season

277 days in Pinal County

Growing Tips for Calendula in Pinal County

Direct sow Calendula outdoors after February 23 in Pinal County when soil has warmed and frost danger has passed.

Sandy soil in Pinal County dries quickly — mulch Calendula with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 98°F in Pinal County, provide afternoon shade for Calendula and water deeply in the morning.

Common pests for Calendula in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Pinal County receives only 16" 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 Pinal County, AZ?

Pinal County is in Zone 9a with an average last frost of February 23. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pinal County, AZ?

Pinal County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is February 23 and first fall frost is November 27.

When should I plant Calendula in Pinal County, AZ?

In Pinal County, AZ, plant Calendula after the last frost (around February 23) and before the first frost (around November 27). Best results when soil holds above 50°F.

What growing zone is Pinal County, AZ for Calendula?

Pinal County sits in USDA Zone 9a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.

Can Calendula grow in Pinal County's climate?

Yes — Calendula grows well in Pinal County's temperate climate. Pinal County averages a 278-day frost-free season, with last frost around February 23 and first frost around November 27.

🌱

Your Pinal County Garden Planner — Free

A 22-page printable planner built for Pinal County (Zone 9a). 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 Pinal County, AZ. 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.