Blog

When to Plant Calendula in Coos County, OR

Coos County, Oregon Zone 9a June

June to-do list for Coos County, Oregon

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Coos County, Oregon.

Avg. last frost March 22
Avg. first frost November 19
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. Basket week: calendula

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Looking ahead to July
  • 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.

Coos County, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Coos County, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Transplant: Feb 7 🌸 Bloom: Mar 21 – Jul 25
Recommended (50%) ✓ Fits season (102 days to spare)
Transplant: Feb 22 🌸 Bloom: Apr 5 – Aug 9
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: Mar 25 🌸 Bloom: May 6 – Sep 9

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 Coos County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Calendula will thrive.

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

5
successive plantings in your 242-day season

Sow every 5.7 weeks. Last sowing by Sep 10 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 5.5" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 2.2" 4.4" 0" ✅ Rainfall sufficient
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 2.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 0.6" 1.6" 🚿 Regular watering
Aug 2.2" 0.8" 1.4" 🚿 Regular watering
Sep 2.2" 1.4" 0.8" 💧 Light watering
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.2" 5.9" 0" ✅ Rainfall sufficient
Dec 5.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Coos 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 ~1,005 GDD — county provides 4,053 GDD Excellent fit

Calendula Planting Timeline — Coos County, OR

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors February 22 Feb 22 – Mar 8
Direct Sow January 25 Jan 25 – Feb 15
Bloom April 5 Apr 5 – Aug 9
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January Direct Sow
February Transplant Outdoors Direct Sow
March Transplant Outdoors
April Bloom
May Bloom
June Bloom
July Bloom
August Fall Sowing Bloom
September Fall Sowing
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 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Calendula in Coos County

Direct sow Calendula outdoors after March 22 in Coos 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 Coos County, OR?

Coos County is in Zone 9a with an average last frost of March 22. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is March 22 and first fall frost is November 19.

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos 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.

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 Coos County, OR. 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.