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When to Plant Chinese Cabbage in Union County, NM

Union County, New Mexico Zone 6b May

What to do in May

Each item below is timed to Union County, New Mexico's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 30
Avg. first frost October 9
Soil temp (4") 42°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
June prep starts now
  • Starting indoors: chinese cabbage
  • First harvests: chinese cabbage

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Chinese cabbage (Napa cabbage) forms elongated, barrel-shaped heads with tender, mild-flavored leaves. It is a staple in Asian cooking, particularly for kimchi.

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 Chinese Cabbage during the growing season. Sandy soil warms quickly in spring — great for early planting — but Chinese Cabbage will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Chinese Cabbage 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
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Union County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Jul 18
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 25 – Jul 23
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jul 12 – Aug 9

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 Union County

How your county's soil matches Chinese Cabbage's growing requirements.

Soil pH

Your soil pH (6.9–8.3) is more alkaline than Chinese Cabbage prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Chinese Cabbage is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Chinese Cabbage.

How to Plant Chinese Cabbage

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 Chinese Cabbage

3
successive plantings in your 162-day season

Sow every 5.7 weeks. Last sowing by Jul 31 to harvest before frost.

For a dedicated fall crop, sow by Jul 31.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.8″/week
Watering frequency 2-3 times/week
Season total 2,589 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Chinese Cabbage

Chinese Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Chinese Cabbage Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 6.5" 0.6" 5.9" 🚿 Regular watering
May 6.5" 0.4" 6.1" 🚿 Regular watering
Jun 6.5" 0.6" 5.9" 🚿 Regular watering
Jul 6.5" 3" 3.5" 🚿 Regular watering
Aug 6.5" 4" 2.5" 💧 Light watering
Sep 6.5" 2.1" 4.4" 🚿 Regular watering
Oct 6.5" 1.4" 5.1" 🚿 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.

Chinese Cabbage 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.

Chinese Cabbage needs ~825 GDD — county provides 2,227 GDD Excellent fit

Chinese Cabbage Planting Timeline — Union County, NM

Chinese Cabbage 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 25 Jun 25 – Jul 23
Fall Sowing July 31 Jul 31 – Aug 14

Plant 1" deep · 15" apart · Rows 24" 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
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

162 days in Union County

Growing Tips for Chinese Cabbage in Union County

Direct sow Chinese Cabbage outdoors after April 30 in Union County when soil has warmed and frost danger has passed.

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

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

Union County receives only 18" of rain annually. Chinese Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Best grown as a fall crop to avoid bolting. Start seeds indoors or direct sow in late summer. Keep soil consistently moist and provide shade in warm weather.

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 Chinese Cabbage in Union County, NM?

Union County is in Zone 6b with an average last frost of April 30. Plan your Chinese Cabbage 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 24-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.

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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 Union 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.