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When to Plant Squash (Summer) in Clallam County, WA

Clallam County, Washington Zone 8b May

This month in Clallam County, Washington

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 23
Avg. first frost October 26
Soil temp (4") 70°F
Watering Moderate
Pest pressure High
Daylight 15 hrs
  1. Set out squash (summer) seedlings

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Get squash (summer) seeds going inside

    These need a head start before your last frost (April 23). Sow into cells now so you're ready to transplant in a few weeks.

To set up a strong June, finish these tasks
  • First harvests: squash (summer)

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Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

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

Clallam County, WA (Zone 8b) Moderate season
186 days
Last Spring Frost April 23
186 growing days
First Fall Frost October 26
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Clallam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Start indoors: Mar 17 Transplant: Apr 28 🍅 Harvest: Jun 16 – Aug 18
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Jun 25 – Aug 27
Safe Start (90%) ✓ Fits season (58 days to spare)
Start indoors: Apr 11 Transplant: May 23 🍅 Harvest: Jul 11 – Sep 12

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 Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (5.7–6.8) overlaps with Squash (Summer)'s range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Squash (Summer)

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Squash (Summer)

4
successive plantings in your 186-day season

Sow every 5.1 weeks. Last sowing by Aug 22 to harvest before frost.

Plant 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 Squash (Summer)

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

Month Squash (Summer) 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.

Squash (Summer) 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.

Squash (Summer) needs ~674 GDD — county provides 2,278 GDD Excellent fit

Squash (Summer) Planting Timeline — Clallam County, WA

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest June 25 Jun 25 – Aug 27

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

186 days in Clallam County

Growing Tips for Squash (Summer) in Clallam County

Direct sow Squash (Summer) outdoors after April 23 in Clallam County when soil has warmed and frost danger has passed.

Your generous 186.0-day season in Clallam County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

Common pests for Squash (Summer) in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Clallam County, WA?

Clallam County is in Zone 8b with an average last frost of April 23. Plan your Squash (Summer) 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.

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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: May 2026.

Sources & credits

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