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When to Plant Napa Cabbage in La Paz County, AZ

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.

La Paz County, Arizona is in USDA Zone 9b. The average last spring frost is February 2 and the first fall frost is December 6, giving you a growing season of approximately 307 days.

At an elevation of 4,875 feet, La Paz County receives approximately 17.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 105ยฐF, so Napa Cabbage may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

La Paz County, AZ (Zone 9b) Year-round
307 days
Last Spring Frost February 2
307 growing days
First Fall Frost December 6

La Paz County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (228 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Mar 15 – Apr 19
Recommended (50%) ✓ Fits season (216 days to spare)
Start indoors: Jan 5 Transplant: Feb 2 🍅 Harvest: Mar 30 – May 4
Safe Start (90%) ✓ Fits season (212 days to spare)
Start indoors: Jan 30 Transplant: Feb 27 🍅 Harvest: Apr 24 – May 29

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.2″/week
You supply
1.5″/week
Watering frequency 2-3 times/week
Season total 4,154 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Napa Cabbage needs ~1,869 GDD — county provides 8,855 GDD Excellent fit

Napa Cabbage Planting Timeline โ€” La Paz County, AZ

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors January 5 Jan 5 โ€“ Jan 19
Transplant Outdoors February 2 Feb 2 โ€“ Feb 16
Direct Sow January 12 Jan 12 โ€“ Feb 2
Fall Sowing October 11 Oct 11 โ€“ Oct 25
Harvest March 30 Mar 30 โ€“ May 4

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

55โ€“75 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 9b

Growing Season

307 days

Growing Tips for La Paz County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Napa Cabbage in La Paz County, AZ?

La Paz County is in Zone 9b with an average last frost of February 2. Plan your Napa Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is La Paz County, AZ?

La Paz County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is February 2 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help La Paz County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

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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 La Paz County, AZ. Local conditions may vary. Last updated: April 2026.