When to Plant Sunflower in Clallam County, WA
May in Clallam County, Washington — your action list
May is a pivotal month for Clallam County, Washington gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Plant out sunflower
Your last frost (April 23) has passed. These warm-season crops can handle outdoor soil now.
June will be here before you know it — start on
- Starting indoors: sunflower
Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.
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.
Clallam County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Clallam County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.7–6.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Clallam County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Sunflower will thrive.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 18 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Sunflower
Sunflower 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 | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.9" | 0" | ❄️ Dormant |
| Feb | — | 5.5" | 0" | ❄️ Dormant |
| Mar | — | 5.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Jul | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Aug | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Sep | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| 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 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.
Sunflower Planting Timeline — Clallam County, WA
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | July 16 | Jul 16 – Sep 3 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
186 days in Clallam County
Growing Tips for Sunflower in Clallam County
Direct sow Sunflower outdoors after April 23 in Clallam County when soil has warmed and frost danger has passed.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
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 24-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.