When to Plant Watermelon in Kitsap County, WA
Your May planting checklist for Kitsap County, Washington
Each item below is timed to Kitsap County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.
June prep starts now
- First harvests: watermelon
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
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 Watermelon during the growing season.
Kitsap County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.3
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 Kitsap County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (5.3–6.3) is more acidic than Watermelon prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Kitsap County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Watermelon will thrive.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jul 28 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Watermelon
Watermelon needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watermelon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.1" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Apr | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| May | 6.5" | 2" | 4.5" | 🚿 Regular watering |
| Jun | 6.5" | 1.3" | 5.2" | 🚿 Regular watering |
| Jul | 6.5" | 0.7" | 5.8" | 🚿 Regular watering |
| Aug | 6.5" | 0.7" | 5.8" | 🚿 Regular watering |
| Sep | 6.5" | 1.4" | 5.1" | 🚿 Regular watering |
| Oct | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Nov | 6.5" | 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.
Watermelon 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.
Watermelon Planting Timeline — Kitsap County, WA
Watermelon 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 | June 10 | Jun 10 – Jul 29 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
70–100 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 Watermelon in Kitsap County
Direct sow Watermelon outdoors after March 25 in Kitsap County when soil has warmed and frost danger has passed.
Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Recommended Watermelon Varieties for Kitsap County
Full-size melons that thrive with your long season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Kitsap County, WA?
Kitsap County is in Zone 9a with an average last frost of March 25. Plan your Watermelon 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.