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When to Plant Arugula in Seward County, NE

Seward County, Nebraska Zone 5b May

Your May game plan for Seward County, Nebraska

A quick May briefing for Seward County, Nebraska gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 21
Avg. first frost October 13
Soil temp (4") 59°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Time to start arugula inside

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. It's harvest week for arugula

    If you can't use it all right away, check the food-preservation section of your planner.

June prep starts now
  • First harvests: 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.

Seward County, Nebraska is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.

At an elevation of 527 feet, Seward County receives approximately 24.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Arugula to ensure they mature before fall.

Seward County, NE (Zone 5b) Moderate season
175 days
Last Spring Frost April 21
175 growing days
First Fall Frost October 13

Seward County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: May 21 – Jul 23
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: May 26 – Jul 28
Safe Start (90%) ✓ Fits season (80 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 6 – Aug 8

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 Seward County

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

Soil pH

Your soil pH (6.4–7.2) overlaps with Arugula's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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

7
successive plantings in your 175-day season

Sow every 3.4 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 36 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.6" 2.8" 0" ✅ Rainfall sufficient
May 2.6" 3.7" 0" ✅ Rainfall sufficient
Jun 2.6" 4.2" 0" ✅ Rainfall sufficient
Jul 2.6" 3.1" 0" ✅ Rainfall sufficient
Aug 2.6" 2.5" 0.1" 💧 Light watering
Sep 2.6" 2.3" 0.3" 💧 Light watering
Oct 2.6" 1.3" 1.3" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Seward 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 ~520 GDD — county provides 2,275 GDD Excellent fit

Arugula Planting Timeline — Seward County, NE

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 7 Apr 7 – Apr 28
Harvest May 26 May 26 – Jul 28
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July Harvest
August Fall Sowing
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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

175 days in Seward County

Growing Tips for Arugula in Seward County

Direct sow Arugula outdoors after April 21 in Seward County when soil has warmed and frost danger has passed.

Your generous 175.0-day season in Seward 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 →

Frequently Asked Questions

When should I plant Arugula in Seward County, NE?

Seward County is in Zone 5b with an average last frost of April 21. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Seward County, NE?

Seward County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 13.

🌱

Your Seward County Garden Planner — Free

A 24-page printable planner built for Seward County (Zone 5b). 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 Seward County, NE. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.