When to Plant Arugula in Kitsap County, WA
Your May gardening checklist
We've pulled the most time-sensitive tasks for Kitsap County, Washington this May and put them front and centre. Tackle them in order.
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Pick arugula
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in June — start thinking about
- First harvests: arugula
Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.
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 Arugula 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 Arugula's growing requirements.
Soil pH
Your soil pH (5.3–6.3) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Kitsap County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Arugula will thrive.
How to Plant Arugula
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Arugula
Sow every 3.4 weeks. Last sowing by Sep 16 to harvest before frost.
For a dedicated fall crop, sow by Sep 10.
Plant Water Budget
Monthly Watering Guide for Arugula
Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Arugula Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.1" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 2" | 0.6" | 💧 Light watering |
| Jun | 2.6" | 1.3" | 1.3" | 🚿 Regular watering |
| Jul | 2.6" | 0.7" | 1.9" | 🚿 Regular watering |
| Aug | 2.6" | 0.7" | 1.9" | 🚿 Regular watering |
| Sep | 2.6" | 1.4" | 1.2" | 💧 Light watering |
| Oct | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 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.
Arugula 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.
Arugula Planting Timeline — Kitsap County, WA
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 25 | Feb 25 – Mar 11 |
| Transplant Outdoors | March 25 | Mar 25 – Apr 8 |
| Direct Sow | March 4 | Mar 4 – Mar 25 |
| Harvest | April 29 | Apr 29 – Jul 1 |
| Fall Sowing | September 10 | Sep 10 – Sep 24 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Harvest |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
225 days in Kitsap County
Growing Tips for Arugula in Kitsap County
Direct sow Arugula 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 Arugula. Sow every 15.0 days for continuous harvest.
Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
Frequently Asked Questions
When should I plant Arugula in Kitsap County, WA?
Kitsap County is in Zone 9a with an average last frost of March 25. Plan your Arugula 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.