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When to plant Arugula in Plummer, ID

In Plummer, plant Arugula in spring between April 24 and May 15, once soil temps hold above 50°F. Plummer's last frost averages May 8, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 23 and August 6 — roughly 30–50 days before the first frost on October 1.

When to Plant Arugula in Plummer, ID

Benewah County, Idaho Zone 6b June

Your June planting checklist for Benewah County, Idaho

Your garden in Benewah County, Idaho is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 8
Avg. first frost October 1
Soil temp (4") 55°F
Watering High
Pest pressure High
Daylight 15.7 hrs
  1. Sow arugula in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Pick arugula

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

Before July arrives, get these ready
  • 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.

Plummer, Idaho is in USDA Zone 6b. The average last spring frost is May 8 and the first fall frost is October 1, giving you a growing season of approximately 146 days.

At an elevation of 6,081 feet, Benewah County receives approximately 20.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Arugula during the growing season.

Plummer, ID (Zone 6b) Short season
146 days
Last Spring Frost May 8
146 growing days
First Fall Frost October 1

Plummer Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Arugula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 3 – Aug 5
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 12 – Aug 14
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 11 – Sep 12

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 Plummer

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

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Arugula prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Arugula.

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 146-day season

Sow every 3.4 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Arugula Water Budget

Plant needs
0.6″/week
Rainfall provides
0.6″/week
Watering frequency Only during dry spells
Season total 3 gal / 100 sq ft
Drought risk

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 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.6" 2.5" 0.1" 💧 Light watering
Jun 2.6" 1.5" 1.1" 💧 Light watering
Jul 2.6" 1.7" 0.9" 💧 Light watering
Aug 2.6" 2.2" 0.4" 💧 Light watering
Sep 2.6" 1.6" 1" 💧 Light watering
Oct 2.6" 1.8" 0.8" 💧 Light watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Benewah 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 ~700 GDD — county provides 2,555 GDD Excellent fit

Arugula Planting Timeline — Plummer, ID

Arugula Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 8 May 8 – May 22
Direct Sow April 24 Apr 24 – May 15
Harvest June 12 Jun 12 – Aug 14
Fall Sowing July 23 Jul 23 – Aug 6

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_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

146 days in Benewah County

Growing Tips for Arugula in Plummer

Direct sow Arugula outdoors after May 08 in Benewah County when soil has warmed and frost danger has passed.

Your generous 146.0-day season in Benewah 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 →

When should I plant Arugula in Plummer, ID?

In Plummer, ID, plant Arugula after the last frost (around May 8) and before the first frost (around October 1). Best results when soil holds above 50°F.

What growing zone is Plummer, ID for Arugula?

Plummer sits in USDA Zone 6b. Arugula grows reliably in zones 3a through 11b, so it's a good fit here.

Can Arugula grow in Plummer's climate?

Yes — Arugula grows well in Plummer's temperate climate. Plummer averages a 146-day frost-free season, with last frost around May 8 and first frost around October 1.

🌱

Your Benewah County Garden Planner — Free

A 22-page printable planner built for Benewah 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 Benewah County, ID. Local conditions may vary. Last updated: June 2026.