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When to plant Calendula in Stanislaus County, CA

In Stanislaus County, plant Calendula in spring between December 23 and January 13, once soil temps hold above 50°F. Stanislaus County's last frost averages February 24, so aim for a steady week of warm soil before planting. For a fall crop, sow between September 5 and September 19 — roughly 50–70 days before the first frost on November 28.

When to Plant Calendula in Stanislaus County, CA

Stanislaus County, California Zone 9b June

This month in Stanislaus County, California

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

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 80°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Start harvesting calendula

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

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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.

Stanislaus County, California is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is November 28, giving you a growing season of approximately 277 days.

At an elevation of 2,887 feet, Stanislaus County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°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
Stanislaus County, CA (Zone 9b) Year-round
277 days
Last Spring Frost February 24
277 growing days
First Fall Frost November 28

Stanislaus County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (170 days to spare)
Transplant: Jan 2 🌸 Bloom: Feb 13 – Jun 5
Recommended (50%) ✓ Fits season (158 days to spare)
Transplant: Jan 20 🌸 Bloom: Mar 3 – Jun 23
Safe Start (90%) ✓ Fits season (123 days to spare)
Transplant: Mar 14 🌸 Bloom: Apr 25 – Aug 15

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 Stanislaus County

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help 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 19 to harvest before frost.

For a dedicated fall crop, sow by Sep 05.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 803 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 3.1" 0" ❄️ Dormant
Feb 2.2" 3.5" 0" ✅ Rainfall sufficient
Mar 2.2" 2.1" 0.1" 💧 Light watering
Apr 2.2" 1.3" 0.9" 💧 Light watering
May 2.2" 0.5" 1.7" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.2" 2" 🚿 Regular watering
Oct 2.2" 0.7" 1.5" 🚿 Regular watering
Nov 2.2" 1.5" 0.7" 💧 Light watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Stanislaus 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 ~1,230 GDD — county provides 5,699 GDD Excellent fit

Calendula Planting Timeline — Stanislaus County, CA

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors January 20 Jan 20 – Feb 3
Direct Sow December 23 Dec 23 – Jan 13
Bloom March 3 Mar 3 – Jun 23
Fall Sowing September 5 Sep 5 – Sep 19

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
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 9b

📆 Growing Season

277 days in Stanislaus County

Growing Tips for Calendula in Stanislaus County

Direct sow Calendula outdoors after February 24 in Stanislaus 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.

Stanislaus County receives only 15" 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 Stanislaus County, CA?

Stanislaus County is in Zone 9b with an average last frost of February 24. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stanislaus County, CA?

Stanislaus County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is November 28.

When should I plant Calendula in Stanislaus County, CA?

In Stanislaus County, CA, plant Calendula after the last frost (around February 24) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Stanislaus County, CA for Calendula?

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

Can Calendula grow in Stanislaus County's climate?

Yes — Calendula grows well in Stanislaus County's temperate climate. Stanislaus County averages a 278-day frost-free season, with last frost around February 24 and first frost around November 28.

🌱

Your Stanislaus County Garden Planner — Free

A 22-page printable planner built for Stanislaus County (Zone 9b). 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 Stanislaus County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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