When to Plant Arugula in Tillamook County, OR
Your May gardening checklist
Your Tillamook County, Oregon garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
-
Fire up the seed-starting tray: arugula
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
-
It's harvest week for arugula
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
June prep starts now
- 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.
Tillamook County, Oregon is in USDA Zone 9a. The average last spring frost is April 19 and the first fall frost is October 29, giving you a growing season of approximately 193 days.
At an elevation of 332 feet, Tillamook County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Arugula during the growing season.
Tillamook County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Tillamook County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Tillamook County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.3%) — 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 09 to harvest before frost.
For a dedicated fall crop, sow by Sep 03.
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 | — | 5.4" | 0" | ❄️ Dormant |
| Feb | — | 4.1" | 0" | ❄️ Dormant |
| Mar | — | 4.1" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 2.5" | 0.1" | 💧 Light watering |
| Jun | 2.6" | 1.8" | 0.8" | 💧 Light watering |
| Jul | 2.6" | 0.7" | 1.9" | 🚿 Regular watering |
| Aug | 2.6" | 0.8" | 1.8" | 🚿 Regular watering |
| Sep | 2.6" | 1.8" | 0.8" | 💧 Light watering |
| Oct | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 6.4" | 0" | ❄️ Dormant |
| Dec | — | 6.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Tillamook 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 — Tillamook County, OR
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | April 19 | Apr 19 – May 3 |
| Direct Sow | March 29 | Mar 29 – Apr 19 |
| Harvest | May 24 | May 24 – Jul 26 |
| Fall Sowing | September 3 | Sep 3 – Sep 17 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors 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
193 days in Tillamook County
Growing Tips for Arugula in Tillamook County
Direct sow Arugula outdoors after April 19 in Tillamook County when soil has warmed and frost danger has passed.
Your generous 193.0-day season in Tillamook 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
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
Frequently Asked Questions
When should I plant Arugula in Tillamook County, OR?
Tillamook County is in Zone 9a with an average last frost of April 19. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Tillamook County, OR?
Tillamook County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 19 and first fall frost is October 29.
Your Tillamook County Garden Planner — Free
A 24-page printable planner built for Tillamook 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.