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When to Plant Spinach in La Plata County, CO

La Plata County, Colorado Zone 6a May

This month in La Plata County, Colorado

A quick May briefing for La Plata County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 31
Avg. first frost September 21
Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Plant out spinach

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Direct-sow spinach

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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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.

La Plata County, Colorado is in USDA Zone 6a. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 5,246 feet, La Plata County receives approximately 14.9 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.

La Plata County, CO (Zone 6a) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21
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La Plata County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 18 – Aug 20
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Apr 26 Transplant: May 31 🍅 Harvest: Jul 5 – Sep 6
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Jul 31 – Oct 2

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 La Plata County

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

Soil pH

Your soil pH (6.2–7.9) overlaps with Spinach's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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

3
successive plantings in your 113-day season

Sow every 4 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 176 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 0.9" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 3" 1.6" 1.4" 💧 Light watering
Jun 3" 0.9" 2.1" 🚿 Regular watering
Jul 3" 1.4" 1.6" 🚿 Regular watering
Aug 3" 1.5" 1.5" 🚿 Regular watering
Sep 3" 1.3" 1.7" 🚿 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 La Plata 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 1,384 GDD Excellent fit

Spinach Planting Timeline — La Plata County, CO

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 – May 10
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 17 May 17 – Jun 7
Harvest July 5 Jul 5 – Sep 6
Fall Sowing July 13 Jul 13 – Jul 27

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

113 days in La Plata County

Growing Tips for Spinach in La Plata County

Direct sow Spinach outdoors after May 31 in La Plata County when soil has warmed and frost danger has passed.

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 La Plata County, CO?

La Plata County is in Zone 6a with an average last frost of May 31. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is La Plata County, CO?

La Plata County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 31 and first fall frost is September 21.

🌱

Your La Plata County Garden Planner — Free

A 24-page printable planner built for La Plata 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 La Plata 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.