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When to Plant Arugula in Huerfano County, CO

Huerfano County, Colorado Zone 6a May

Your May game plan for Huerfano County, Colorado

May is a pivotal month for Huerfano County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Get arugula in the ground

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

June prep starts now
  • Starting indoors: arugula
  • 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.

Huerfano County, Colorado is in USDA Zone 6a. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 7,235 feet, Huerfano County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Arugula to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Arugula successfully. Mulch heavily to conserve soil moisture.

Huerfano County, CO (Zone 6a) Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30

Huerfano County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 12 – Aug 14
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jun 16 – Aug 18
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: May 10 Transplant: Jun 14 🍅 Harvest: Jul 19 – Sep 20

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 Huerfano County

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

Soil pH

Your soil pH (6.3–7.7) overlaps with Arugula's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Arugula.

Organic Matter

Organic matter is moderate (2.8%). 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 141-day season

Sow every 3.4 weeks. Last sowing by Aug 11 to harvest before frost.

For a dedicated fall crop, sow by Jul 22.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.5″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 493 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 2.6" 1.6" 1" 💧 Light watering
Jun 2.6" 1.1" 1.5" 🚿 Regular watering
Jul 2.6" 1.2" 1.4" 🚿 Regular watering
Aug 2.6" 1.8" 0.8" 💧 Light watering
Sep 2.6" 1.1" 1.5" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Huerfano 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 ~490 GDD — county provides 1,727 GDD Excellent fit

Arugula Planting Timeline — Huerfano County, CO

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 22 Jul 22 – Aug 5

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 · 1-2 times/week

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

141 days in Huerfano County

Growing Tips for Arugula in Huerfano County

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

Your generous 141.0-day season in Huerfano 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 Huerfano County, CO?

Huerfano County is in Zone 6a with an average last frost of May 12. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Huerfano County, CO?

Huerfano County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 12 and first fall frost is September 30.

🌱

Your Huerfano County Garden Planner — Free

A 24-page printable planner built for Huerfano 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 Huerfano County, CO. 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.