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When to Plant Arugula in Osborne County, KS

Osborne County, Kansas Zone 6a May

Osborne County, Kansas gardeners: here's your May plan

Welcome to May in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 23
Avg. first frost October 14
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Begin indoor sowing: arugula

    These need a head start before your last frost (April 23). Sow into cells now so you're ready to transplant in a few weeks.

  2. Bring in the arugula

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

A few tasks this May that'll pay off in June
  • 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.

Osborne County, Kansas is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 14, giving you a growing season of approximately 174 days.

At an elevation of 608 feet, Osborne County receives approximately 31.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Arugula during the growing season.

Osborne County, KS (Zone 6a) Moderate season
174 days
Last Spring Frost April 23
174 growing days
First Fall Frost October 14
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Osborne County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jul 24
Recommended (50%) ✓ Fits season (76 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jul 30
Safe Start (90%) ✓ Fits season (74 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jun 11 – Aug 13

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 Osborne County

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

Soil pH

Your soil pH (6.8–7.5) is more alkaline than Arugula prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — 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

7
successive plantings in your 174-day season

Sow every 3.4 weeks. Last sowing by Aug 25 to harvest before frost.

For a dedicated fall crop, sow by Aug 05.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.6" 3.8" 0" ✅ Rainfall sufficient
May 2.6" 4.3" 0" ✅ Rainfall sufficient
Jun 2.6" 4.5" 0" ✅ Rainfall sufficient
Jul 2.6" 3.9" 0" ✅ Rainfall sufficient
Aug 2.6" 4.2" 0" ✅ Rainfall sufficient
Sep 2.6" 3" 0" ✅ Rainfall sufficient
Oct 2.6" 2.1" 0.5" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Osborne 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 ~610 GDD — county provides 2,653 GDD Excellent fit

Arugula Planting Timeline — Osborne County, KS

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest May 28 May 28 – Jul 30
Fall Sowing August 5 Aug 5 – Aug 19

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6a

📆 Growing Season

174 days in Osborne County

Growing Tips for Arugula in Osborne County

Direct sow Arugula outdoors after April 23 in Osborne County when soil has warmed and frost danger has passed.

Your generous 174.0-day season in Osborne 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 Osborne County, KS?

Osborne County is in Zone 6a with an average last frost of April 23. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Osborne County, KS?

Osborne County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 14.

🌱

Your Osborne County Garden Planner — Free

A 24-page printable planner built for Osborne County (Zone 6a). 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 Osborne County, KS. 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.