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When to Plant Spinach in Colfax County, NM

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.

Colfax County, New Mexico is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is September 26, giving you a growing season of approximately 134 days.

At an elevation of 5,131 feet, Colfax County receives approximately 15.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Spinach to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Spinach will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.

Colfax County, NM (Zone 5a) Short season
134 days
Last Spring Frost May 15
134 growing days
First Fall Frost September 26

Colfax County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.1-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jun 10 – Aug 12
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jun 19 – Aug 21
Safe Start (90%) ✓ Fits season (20 days to spare)
Start indoors: May 12 Transplant: Jun 16 🍅 Harvest: Jul 21 – Sep 22

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 Colfax County

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

Soil pH

Your soil pH (7.1โ€“8.1) is more alkaline than Spinach prefers (6.5โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Colfax County warms quickly in spring but drains fast. Spinach will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Spinach.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting 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 134-day season

Sow every 4 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 607 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Spinach needs ~552 GDD — county provides 1,742 GDD Excellent fit

Spinach Planting Timeline โ€” Colfax County, NM

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 โ€“ Apr 24
Transplant Outdoors May 15 May 15 โ€“ May 29
Direct Sow May 1 May 1 โ€“ May 22
Fall Sowing July 18 Jul 18 โ€“ Aug 1
Harvest June 19 Jun 19 โ€“ Aug 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

35โ€“50 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

134 days in Colfax County

Growing Tips for Spinach in Colfax County

Direct sow Spinach outdoors after May 15 in Colfax County when soil has warmed and frost danger has passed.

Sandy soil in Colfax County dries quickly โ€” mulch Spinach with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 134.0-day season in Colfax 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

Level Up Your Garden

๐ŸŒพ 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 35ยฐF, under 45% humidity.

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

Frequently Asked Questions

When should I plant Spinach in Colfax County, NM?

Colfax County is in Zone 5a with an average last frost of May 15. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Colfax County, NM?

Colfax County, New Mexico is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Colfax County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Colfax County, NM. Local conditions may vary. Last updated: April 2026.