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When to Plant Zucchini in Kitsap County, WA

Kitsap County, Washington Zone 9a May

May in the garden — Kitsap County, Washington

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

Avg. last frost March 25
Avg. first frost November 5
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Collect zucchini at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to June
  • First harvests: zucchini

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Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Kitsap County, Washington is in USDA Zone 9a. The average last spring frost is March 25 and the first fall frost is November 5, giving you a growing season of approximately 225 days.

At an elevation of 264 feet, Kitsap County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Zucchini during the growing season.

Kitsap County, WA (Zone 9a) Long season
225 days
Last Spring Frost March 25
225 growing days
First Fall Frost November 5

Kitsap County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 15 – Jul 10
Recommended (50%) ✓ Fits season (113 days to spare)
Start indoors: Feb 25 Transplant: Apr 1 🍅 Harvest: May 20 – Jul 15
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 10 – Aug 5

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 Kitsap County

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

Soil pH

Your soil pH (5.3–6.3) is more acidic than Zucchini prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Zucchini will thrive.

How to Plant Zucchini

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

Succession Planting Zucchini

6
successive plantings in your 225-day season

Sow every 5.1 weeks. Last sowing by Sep 06 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 983 gal / 100 sq ft

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 5.1" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 5.2" 4.3" 0.9" 💧 Light watering
Apr 5.2" 2.7" 2.5" 💧 Light watering
May 5.2" 2" 3.2" 🚿 Regular watering
Jun 5.2" 1.3" 3.9" 🚿 Regular watering
Jul 5.2" 0.7" 4.5" 🚿 Regular watering
Aug 5.2" 0.7" 4.5" 🚿 Regular watering
Sep 5.2" 1.4" 3.8" 🚿 Regular watering
Oct 5.2" 2.9" 2.3" 💧 Light watering
Nov 5.2" 6.5" 0" ✅ Rainfall sufficient
Dec 6" 0" ❄️ Dormant

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

Zucchini 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.

Zucchini needs ~722 GDD — county provides 3,093 GDD Excellent fit

Zucchini Planting Timeline — Kitsap County, WA

Zucchini Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors April 1 Apr 1 – Apr 15
Direct Sow March 25 Mar 25 – Apr 15
Harvest May 20 May 20 – Jul 15

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

225 days in Kitsap County

Growing Tips for Zucchini in Kitsap County

Direct sow Zucchini outdoors after March 25 in Kitsap County when soil has warmed and frost danger has passed.

Your generous 225.0-day season in Kitsap County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

Common pests for Zucchini 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. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Kitsap County, WA?

Kitsap County is in Zone 9a with an average last frost of March 25. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kitsap County, WA?

Kitsap County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is March 25 and first fall frost is November 5.

🌱

Your Kitsap County Garden Planner — Free

A 24-page printable planner built for Kitsap County (Zone 9a). 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 Kitsap 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.