Blog

When to Plant Calendula in Carson, WA

Skamania County, Washington Zone 8a June

June in the garden — Skamania County, Washington

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

Avg. last frost April 18
Avg. first frost October 19
Soil temp (4") 76°F
Watering High
Pest pressure High
Daylight 15.5 hrs
  1. Harvest calendula as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

July will be here before you know it — start on
  • 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.

Carson, Washington is in USDA Zone 8a. The average last spring frost is April 18 and the first fall frost is October 19, giving you a growing season of approximately 184 days.

At an elevation of 16 feet, Skamania County receives approximately 43 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Calendula to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Carson, WA (Zone 8a) Moderate season
184 days
Last Spring Frost April 18
184 growing days
First Fall Frost October 19

Carson Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Transplant: Mar 29 🌸 Bloom: May 17 – Sep 27
Recommended (50%) ✓ Fits season (16 days to spare)
Transplant: Apr 4 🌸 Bloom: May 23 – Oct 3
Safe Start (90%) ✓ Fits season (24 days to spare)
Transplant: Apr 26 🌸 Bloom: Jun 14 – Oct 25

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 Carson

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

Soil pH

Your soil pH (5.6–6.2) is within Calendula's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Calendula will thrive.

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 184-day season

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

For a dedicated fall crop, sow by Aug 10.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 6.5" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 2.1" 0.1" 💧 Light watering
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 0.7" 1.5" 🚿 Regular watering
Aug 2.2" 0.7" 1.5" 🚿 Regular watering
Sep 2.2" 1.8" 0.4" 💧 Light watering
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 7.4" 0" ❄️ Dormant
Dec 7.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Skamania 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 ~555 GDD — county provides 1,702 GDD Excellent fit

Calendula Planting Timeline — Carson, WA

Calendula Planting Calendar

Activity When Date Range
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 7 Mar 7 – Mar 28
Bloom May 23 May 23 – Oct 3
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April Transplant Outdoors
May Bloom
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 8a

📆 Growing Season

184 days in Skamania County

Growing Tips for Calendula in Carson

Direct sow Calendula outdoors after April 18 in Skamania 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 →

🌱

Your Skamania County Garden Planner — Free

A 22-page printable planner built for Skamania County (Zone 8a). 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 Skamania County, WA. Local conditions may vary. Last updated: June 2026.