When to Plant Arugula in Chelan County, WA
Top priorities for Chelan County, Washington gardeners in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
-
Get arugula seeds going inside
You're about 21 weeks out from your last frost — the perfect window to get these germinating indoors.
-
Collect arugula at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Looking ahead to June
- 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.
Chelan County, Washington is in USDA Zone 7a. The average last spring frost is April 24 and the first fall frost is October 20, giving you a growing season of approximately 179 days.
At an elevation of 3,517 feet, Chelan County receives approximately 14.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Arugula during the growing season. With low rainfall, drip irrigation is essential for growing Arugula successfully. Mulch heavily to conserve soil moisture.
Chelan County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.3
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 Chelan County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (5.5–6.3) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Chelan County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Arugula will thrive.
How to Plant Arugula
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Arugula
Sow every 3.4 weeks. Last sowing by Aug 31 to harvest before frost.
For a dedicated fall crop, sow by Aug 11.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 2.1" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| May | 2.6" | 0.9" | 1.7" | 🚿 Regular watering |
| Jun | 2.6" | 0.6" | 2" | 🚿 Regular watering |
| Jul | 2.6" | 0.2" | 2.4" | 🚿 Regular watering |
| Aug | 2.6" | 0.3" | 2.3" | 🚿 Regular watering |
| Sep | 2.6" | 0.5" | 2.1" | 🚿 Regular watering |
| Oct | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| Nov | — | 1.9" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Chelan 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 — Chelan County, WA
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Harvest | May 29 | May 29 – Jul 31 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · 1-2 times/week
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
179 days in Chelan County
Growing Tips for Arugula in Chelan County
Direct sow Arugula outdoors after April 24 in Chelan County when soil has warmed and frost danger has passed.
Your generous 179.0-day season in Chelan 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 Chelan County, WA?
Chelan County is in Zone 7a with an average last frost of April 24. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Chelan County, WA?
Chelan County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 24 and first fall frost is October 20.
Your Chelan County Garden Planner — Free
A 24-page printable planner built for Chelan County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.