Blog

When to Plant Spinach in Los Alamos County, NM

Los Alamos County, New Mexico Zone 7a May

Your May planting checklist for Los Alamos County, New Mexico

A quick May briefing for Los Alamos County, New Mexico gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 10
Avg. first frost October 7
Soil temp (4") 49°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Move spinach into the garden

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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

Instant PDF download. No spam, unsubscribe any time.

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.

Los Alamos County, New Mexico is in USDA Zone 7a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 5,220 feet, Los Alamos County receives approximately 12.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Spinach during the growing season. Sandy soil warms quickly in spring — great for early planting — 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.

Los Alamos County, NM (Zone 7a) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7
Share this guide:

Los Alamos County Soil Profile

Soil Type

Sandy Loam

Soil pH

7-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jun 14 – Aug 16
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Apr 21 Transplant: May 26 🍅 Harvest: Jun 30 – Sep 1

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 Los Alamos County

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

Soil pH

Your soil pH (7.0–8.6) is more alkaline than Spinach prefers (6.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Los Alamos 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 (0.8%). 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

5
successive plantings in your 150-day season

Sow every 4 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Jul 29.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 915 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.6" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.4" 0" ❄️ Dormant
May 3" 0.3" 2.7" 🚿 Regular watering
Jun 3" 0.4" 2.6" 🚿 Regular watering
Jul 3" 1.9" 1.1" 💧 Light watering
Aug 3" 2.4" 0.6" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 3" 1.1" 1.9" 🚿 Regular watering
Nov 0.7" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Los Alamos 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 ~648 GDD — county provides 2,287 GDD Excellent fit

Spinach Planting Timeline — Los Alamos County, NM

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 26 Apr 26 – May 17
Harvest June 14 Jun 14 – Aug 16
Fall Sowing July 29 Jul 29 – Aug 12

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
Share this guide:

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: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

150 days in Los Alamos County

Growing Tips for Spinach in Los Alamos County

Direct sow Spinach outdoors after May 10 in Los Alamos County when soil has warmed and frost danger has passed.

Sandy soil in Los Alamos County dries quickly — mulch Spinach with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 150.0-day season in Los Alamos 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.

Recommended Spinach Varieties for Los Alamos County

Slow-bolting spinach for warm springs — best as fall crop here

Bloomsdale Long Standing Tyee Space

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 Los Alamos County, NM?

Los Alamos County is in Zone 7a with an average last frost of May 10. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Los Alamos County, NM?

Los Alamos County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 10 and first fall frost is October 7.

🌱

Your Los Alamos County Garden Planner — Free

A 24-page printable planner built for Los Alamos County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Los Alamos County, NM. 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.