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When to Plant Calendula in Yakima County, WA

Yakima County, Washington Zone 7a August

August in Yakima County, Washington — your action list

A quick August briefing for Yakima County, Washington gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 6
Avg. first frost October 3
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for calendula

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

  2. Direct-sow calendula for cool weather

    Your first frost is about 7 weeks away — plenty of time for these to mature.

September prep starts now
  • 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.

Yakima County, Washington is in USDA Zone 7a. The average last spring frost is May 6 and the first fall frost is October 3, giving you a growing season of approximately 150 days.

At an elevation of 3,150 feet, Yakima County receives approximately 18 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°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
Yakima County, WA (Zone 7a) Moderate season
150 days
Last Spring Frost May 6
150 growing days
First Fall Frost October 3

Yakima County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 19 Transplant: Apr 30 🌸 Bloom: Jun 18 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Mar 25 Transplant: May 6 🌸 Bloom: Jun 24 – Oct 7
Safe Start (90%) ✗ May not fit
Start indoors: Apr 14 Transplant: May 26 🌸 Bloom: Jul 14 – Oct 27

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 Yakima County

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

Soil pH

Your soil pH (5.5–6.3) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Calendula will thrive.

How to Plant Calendula

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Calendula

3
successive plantings in your 150-day season

Sow every 5.7 weeks. Last sowing by Jul 25 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/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 2.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 2.2" 1" 1.2" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 0.3" 1.9" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.6" 1.6" 🚿 Regular watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Yakima 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 ~870 GDD — county provides 2,175 GDD Excellent fit

Calendula Planting Timeline — Yakima County, WA

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 1 Apr 1 – Apr 22
Bloom June 24 Jun 24 – Oct 7
Fall Sowing August 8 Aug 8 – Aug 22

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
June Bloom
July Bloom
August Fall Sowing Bloom
September Bloom
October Bloom
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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

150 days in Yakima County

Growing Tips for Calendula in Yakima County

Direct sow Calendula outdoors after May 06 in Yakima 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.

Yakima County receives only 18" 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 Yakima County, WA?

Yakima County is in Zone 7a with an average last frost of May 6. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yakima County, WA?

Yakima County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 6 and first fall frost is October 3.

🌱

Your Yakima County Garden Planner — Free

A 22-page printable planner built for Yakima County (Zone 7a). 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 Yakima County, WA. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.