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When to Plant Collard Greens in Dona Ana County, NM

Dona Ana County, New Mexico Zone 8b May

Your May game plan for Dona Ana County, New Mexico

Your Dona Ana County, New Mexico garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 30
Avg. first frost October 30
Soil temp (4") 59°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Get collard greens seeds going inside

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Collect collard greens at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Before June arrives, get these ready
  • First harvests: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Dona Ana County, New Mexico is in USDA Zone 8b. The average last spring frost is March 30 and the first fall frost is October 30, giving you a growing season of approximately 214 days.

At an elevation of 4,516 feet, Dona Ana County receives approximately 14.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Collard Greens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Collard Greens will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.

Dona Ana County, NM (Zone 8b) Long season
214 days
Last Spring Frost March 30
214 growing days
First Fall Frost October 30

Dona Ana County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Jan 29 Transplant: Mar 5 🍅 Harvest: Apr 30 – Jul 2
Recommended (50%) ✓ Fits season (95 days to spare)
Start indoors: Feb 23 Transplant: Mar 30 🍅 Harvest: May 25 – Jul 27
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 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 Dona Ana County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (7.3–8.9) is more alkaline than Collard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Dona Ana County warms quickly in spring but drains fast. Collard Greens will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Collard Greens.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Collard Greens.

How to Plant Collard Greens

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

4
successive plantings in your 214-day season

Sow every 6.3 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Aug 21.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.3″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,744 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Collard Greens

Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Collard Greens Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 3.5" 0.8" 2.7" 🚿 Regular watering
Apr 3.5" 0.4" 3.1" 🚿 Regular watering
May 3.5" 0.3" 3.2" 🚿 Regular watering
Jun 3.5" 0.6" 2.9" 🚿 Regular watering
Jul 3.5" 2.6" 0.9" 💧 Light watering
Aug 3.5" 2.7" 0.8" 💧 Light watering
Sep 3.5" 1.7" 1.8" 🚿 Regular watering
Oct 3.5" 1.2" 2.3" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Collard Greens 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.

Collard Greens needs ~1,430 GDD — county provides 4,708 GDD Excellent fit

Collard Greens Planting Timeline — Dona Ana County, NM

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors March 30 Mar 30 – Apr 13
Direct Sow March 16 Mar 16 – Apr 6
Harvest May 25 May 25 – Jul 27
Fall Sowing August 21 Aug 21 – Sep 4

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 2-3 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

214 days in Dona Ana County

Growing Tips for Collard Greens in Dona Ana County

Direct sow Collard Greens outdoors after March 30 in Dona Ana County when soil has warmed and frost danger has passed.

Sandy soil in Dona Ana County dries quickly — mulch Collard Greens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Dona Ana County, provide afternoon shade for Collard Greens and water deeply in the morning.

Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Dona Ana County, NM?

Dona Ana County is in Zone 8b with an average last frost of March 30. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dona Ana County, NM?

Dona Ana County, New Mexico is in USDA Hardiness Zone 8b. The average last spring frost is March 30 and first fall frost is October 30.

🌱

Your Dona Ana County Garden Planner — Free

A 24-page printable planner built for Dona Ana County (Zone 8b). 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 Dona Ana 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.