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When to Plant Spinach in Union County, NM

Spinach

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.

Union County, New Mexico is in USDA Zone 6b. The average last spring frost is April 30 and the first fall frost is October 9, giving you a growing season of approximately 162 days.

At an elevation of 6,384 feet, Union County receives approximately 17.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 85°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.

Union County, NM (Zone 6b) Moderate season
162 days
Last Spring Frost April 30
162 growing days
First Fall Frost October 9

Union County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.3

Drainage

Well Drained

Monthly Watering Guide for Spinach

Spinach needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 4.3" 0.6" 3.7" 🚿 Regular watering
May 4.3" 0.4" 3.9" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Union County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Spinach Planting Timeline — Union County, NM

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest June 4 Jun 4 – Aug 6
Fall Sowing July 31 Jul 31 – Aug 14

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors 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

Moderate — regular watering

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

162 days in Union County

Growing Tips for Union County

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 Union County, NM?

Union County is in Zone 6b with an average last frost of April 30. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, NM?

Union County, New Mexico is in USDA Hardiness Zone 6b. The average last spring frost is April 30 and first fall frost is October 9.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 6b). 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 Union County, NM. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.