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When to Plant Sunflower in Clallam County, WA

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Clallam County, Washington is in USDA Zone 8b. The average last spring frost is April 23 and the first fall frost is October 26, giving you a growing season of approximately 186 days.

At an elevation of 194 feet, Clallam County receives approximately 54.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sunflower to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Clallam County, WA (Zone 8b) Moderate season
186 days
Last Spring Frost April 23
186 growing days
First Fall Frost October 26

Clallam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Monthly Watering Guide for Sunflower

Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan 8.9" 0" ❄️ Dormant
Feb 5.5" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 4.3" 4.6" 0" ✅ Rainfall sufficient
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 1.1" 3.2" 🚿 Regular watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 9.1" 0" ❄️ Dormant
Dec 7.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clallam County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunflower Planting Timeline — Clallam County, WA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow April 9 Apr 9 – Apr 30
Bloom July 2 Jul 2 – Nov 19

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

186 days in Clallam County

Growing Tips for Clallam County

Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Clallam County, WA?

Clallam County is in Zone 8b with an average last frost of April 23. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clallam County, WA?

Clallam County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 23 and first fall frost is October 26.

🌱

Your Clallam County Garden Planner — Free

A 22-page printable planner built for Clallam County (Zone 8b). 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 Clallam County, WA. 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.