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When to Plant Spinach in Huerfano County, CO

Huerfano County, Colorado Zone 6a May

This month in Huerfano County, Colorado

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

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Move spinach into the garden

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

A few tasks this May that'll pay off in June
  • Starting indoors: spinach
  • First harvests: spinach

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Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.

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 Spinach to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Spinach 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 Spinach's growing requirements.

Soil pH

Your soil pH (6.3–7.7) overlaps with Spinach's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Spinach.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Spinach.

How to Plant Spinach

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 Spinach

4
successive plantings in your 141-day season

Sow every 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
0.7″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 689 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Spinach

Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 3" 1.6" 1.4" 💧 Light watering
Jun 3" 1.1" 1.9" 🚿 Regular watering
Jul 3" 1.2" 1.8" 🚿 Regular watering
Aug 3" 1.8" 1.2" 💧 Light watering
Sep 3" 1.1" 1.9" 🚿 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.

Spinach 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.

Spinach needs ~521 GDD — county provides 1,727 GDD Excellent fit

Spinach Planting Timeline — Huerfano County, CO

Spinach 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

0.7"/week · 1-2 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

141 days in Huerfano County

Growing Tips for Spinach in Huerfano County

Direct sow Spinach 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 Spinach. Sow every 17.0 days for continuous harvest.

General growing tips

Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Huerfano County, CO?

Huerfano County is in Zone 6a with an average last frost of May 12. Plan your Spinach 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.