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When to Plant Hydrangeas in Clallam County, WA

Clallam County, Washington Zone 8b June

June in the garden — Clallam County, Washington

Each item below is timed to Clallam County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 23
Avg. first frost October 26
Soil temp (4") 80°F
Watering High
Pest pressure High
Daylight 15.8 hrs
  1. Sow hydrangeas in trays indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Harvest hydrangeas as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

July will be here before you know it — start on
  • First harvests: hydrangeas

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Hydrangeas (Hydrangea spp.) are among the most spectacular summer-blooming shrubs, with large mophead, lacecap, or panicle flower clusters lasting weeks in the garden and drying beautifully for arrangements. Native to Asia and North America alike, the genus spans several garden species with different hardiness and blooming habits. Panicle hydrangeas (H. paniculata, e.g., Limelight) are the most cold-hardy (Zone 3) and most reliable bloomers; smooth hydrangeas (H. arborescens, e.g., Annabelle) are equally tough. Bigleaf hydrangeas (H. macrophylla) are prized for blue/pink color-shifting blooms but require reliable snow cover or winter protection in Zones 5–6. Flower color in macrophylla types is determined by soil pH (acidic = blue, alkaline = pink).

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 Hydrangeas to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hydrangeas root diseases.

Perennial 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

Hydrangeas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 10 Transplant: Apr 7 🌸 Bloom: Jun 16 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Feb 19 Transplant: Apr 16 🌸 Bloom: Jun 25 – Oct 29
Safe Start (90%) ✗ May not fit
Start indoors: Mar 7 Transplant: May 2 🌸 Bloom: Jul 11 – Nov 14

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 Hydrangeas's growing requirements.

Soil pH

Your soil pH (5.7–6.8) overlaps with Hydrangeas's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Hydrangeas

1"
Planting Depth
48"
Between Plants
60"
Between Rows

Hydrangeas Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Hydrangeas

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

Month Hydrangeas 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.

Hydrangeas 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.

Hydrangeas needs ~1,470 GDD — county provides 2,278 GDD Excellent fit

Hydrangeas Planting Timeline — Clallam County, WA

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 16 Apr 16 – Apr 30
Bloom June 25 Jun 25 – Oct 29

Plant 1" deep · 48" apart · Rows 60" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

186 days in Clallam County

Growing Tips for Hydrangeas in Clallam County

Direct sow Hydrangeas outdoors after April 23 in Clallam County when soil has warmed and frost danger has passed.

General growing tips

Plant container-grown specimens in spring or fall, spacing at least 3–5 feet apart to allow for mature shrub spread. Most hydrangeas prefer morning sun with afternoon shade, especially in Zones 7+. Keep consistently moist — the name derives from the Greek for water vessel. Prune panicle and smooth types in late winter/early spring (they bloom on new wood). Prune bigleaf types only lightly after bloom; cutting stems in fall removes next year's buds. In Zone 5–6, protect bigleaf varieties with burlap or wire cages filled with leaves over winter. Fall planting (Zones 5+) gives excellent root establishment before summer heat. Year 2+ plants reach full size and bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hydrangeas in Clallam County, WA?

Clallam County is in Zone 8b with an average last frost of April 23. Plan your Hydrangeas 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.