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When to Plant Napa Cabbage in Greenlee County, AZ

Greenlee County, Arizona Zone 8a May

May in the garden — Greenlee County, Arizona

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

Avg. last frost April 22
Avg. first frost October 22
Soil temp (4") 59°F
Watering Critical
Pest pressure Moderate
Daylight 13.7 hrs
  1. Indoor seed-starting week for napa cabbage

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Before June arrives, get these ready
  • First harvests: napa cabbage

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Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

Greenlee County, Arizona is in USDA Zone 8a. The average last spring frost is April 22 and the first fall frost is October 22, giving you a growing season of approximately 183 days.

At an elevation of 4,156 feet, Greenlee County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Napa Cabbage may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Napa Cabbage will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Napa Cabbage successfully. Mulch heavily to conserve soil moisture.

Greenlee County, AZ (Zone 8a) Moderate season
183 days
Last Spring Frost April 22
183 growing days
First Fall Frost October 22

Greenlee County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.1-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 10
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (62 days to spare)
Start indoors: May 14 Transplant: Jun 18 🍅 Harvest: Aug 13 – Sep 17

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 Greenlee County

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

Soil pH

Your soil pH (7.1–8.3) is more alkaline than Napa Cabbage prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Napa 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 Napa Cabbage.

How to Plant Napa 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 Napa Cabbage

3
successive plantings in your 183-day season

Sow every 6.3 weeks. Last sowing by Aug 08 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.3″/week
You supply
1.9″/week
Watering frequency 2-3 times/week
Season total 3,165 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Napa Cabbage

Napa 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 Napa Cabbage Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 6.5" 0.5" 6" 🚿 Regular watering
May 6.5" 0.4" 6.1" 🚿 Regular watering
Jun 6.5" 0.5" 6" 🚿 Regular watering
Jul 6.5" 2.7" 3.8" 🚿 Regular watering
Aug 6.5" 2.9" 3.6" 🚿 Regular watering
Sep 6.5" 1.7" 4.8" 🚿 Regular watering
Oct 6.5" 1.3" 5.2" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Napa 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.

Napa Cabbage needs ~1,381 GDD — county provides 3,888 GDD Excellent fit

Napa Cabbage Planting Timeline — Greenlee County, AZ

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 22 Apr 22 – May 6
Direct Sow April 8 Apr 8 – Apr 29
Harvest June 17 Jun 17 – Jul 22
Fall Sowing August 13 Aug 13 – Aug 27

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
June Harvest
July Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

183 days in Greenlee County

Growing Tips for Napa Cabbage in Greenlee County

Direct sow Napa Cabbage outdoors after April 22 in Greenlee County when soil has warmed and frost danger has passed.

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

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

Greenlee County receives only 14" of rain annually. Napa Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Greenlee County, AZ?

Greenlee County is in Zone 8a with an average last frost of April 22. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greenlee County, AZ?

Greenlee County, Arizona is in USDA Hardiness Zone 8a. The average last spring frost is April 22 and first fall frost is October 22.

🌱

Your Greenlee County Garden Planner — Free

A 24-page printable planner built for Greenlee County (Zone 8a). 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 Greenlee County, AZ. 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.