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When to Plant Arugula in Elgin, OR

Union County, Oregon Zone 6b June

Your June game plan for Union County, Oregon

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

Avg. last frost May 12
Avg. first frost September 26
Soil temp (4") 62°F
Watering Critical
Pest pressure High
Daylight 15.4 hrs
  1. Start arugula under lights

    Label every cell. You will absolutely forget which is which otherwise.

  2. Basket week: arugula

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July will be here before you know it — start on
  • First harvests: arugula
  • Fall sowing: arugula

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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.

Elgin, Oregon is in USDA Zone 6b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.

At an elevation of 2,751 feet, Union County receives approximately 23.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Arugula during the growing season.

Elgin, OR (Zone 6b) Short season
137 days
Last Spring Frost May 12
137 growing days
First Fall Frost September 26

Elgin Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Arugula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 7 – Aug 9
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jun 16 – Aug 18
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: May 4 Transplant: Jun 8 🍅 Harvest: Jul 13 – Sep 14

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 Elgin

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

Soil pH

Your soil pH (5.2–6.6) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Arugula.

Organic Matter

Organic matter is excellent (5.6%) — Arugula will thrive.

How to Plant Arugula

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Arugula

5
successive plantings in your 137-day season

Sow every 3.4 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Arugula Water Budget

Plant needs
0.6″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 73 gal / 100 sq ft

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 2.9" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 2.6" 1.5" 1.1" 💧 Light watering
Jun 2.6" 0.9" 1.7" 🚿 Regular watering
Jul 2.6" 0.4" 2.2" 🚿 Regular watering
Aug 2.6" 0.5" 2.1" 🚿 Regular watering
Sep 2.6" 1" 1.6" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 3.8" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Union 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 needs ~580 GDD — county provides 1,986 GDD Excellent fit

Arugula Planting Timeline — Elgin, OR

Arugula Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 12 May 12 – May 26
Direct Sow April 28 Apr 28 – May 19
Harvest June 16 Jun 16 – Aug 18
Fall Sowing July 18 Jul 18 – Aug 1

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.6"/week · Only during dry spells

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

137 days in Union County

Growing Tips for Arugula in Elgin

Direct sow Arugula outdoors after May 12 in Union County when soil has warmed and frost danger has passed.

Your generous 137.0-day season in Union 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 6b). 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 Union County, OR. Local conditions may vary. Last updated: June 2026.