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When to Plant Napa Cabbage in Santa Barbara County, CA

Santa Barbara County, California Zone 10a May

What to do in May

A quick May briefing for Santa Barbara County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 28
Avg. first frost November 24
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. Collect napa cabbage at their peak

    If you can't use it all right away, check the food-preservation section of your planner.

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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.

Santa Barbara County, California is in USDA Zone 10a. The average last spring frost is February 28 and the first fall frost is November 24, giving you a growing season of approximately 269 days.

At an elevation of 2,364 feet, Santa Barbara County receives approximately 19.9 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Napa Cabbage during the growing season. With low rainfall, drip irrigation is essential for growing Napa Cabbage successfully. Mulch heavily to conserve soil moisture.

Santa Barbara County, CA (Zone 10a) Long season
269 days
Last Spring Frost February 28
269 growing days
First Fall Frost November 24
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Santa Barbara County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (182 days to spare)
Start indoors: Jan 15 Transplant: Feb 12 🍅 Harvest: Apr 9 – May 14
Recommended (50%) ✓ Fits season (178 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Apr 25 – May 30
Safe Start (90%) ✓ Fits season (166 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 7

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 Santa Barbara County

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

Soil pH

Your soil pH (6.5–7.2) is within Napa Cabbage's preferred range (6.0–7.5).

Soil Texture

The loam soil in Santa Barbara County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Napa Cabbage.

How to Plant Napa Cabbage

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Napa Cabbage

5
successive plantings in your 269-day season

Sow every 6.3 weeks. Last sowing by Sep 10 to harvest before frost.

For a dedicated fall crop, sow by Sep 29.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.3″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,433 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 4" 0" ❄️ Dormant
Feb 6.5" 4.6" 1.9" 💧 Light watering
Mar 6.5" 2.9" 3.6" 🚿 Regular watering
Apr 6.5" 1.8" 4.7" 🚿 Regular watering
May 6.5" 0.5" 6" 🚿 Regular watering
Jun 6.5" 0.1" 6.4" 🚿 Regular watering
Jul 6.5" 0" 6.5" 🚿 Regular watering
Aug 6.5" 0" 6.5" 🚿 Regular watering
Sep 6.5" 0.2" 6.3" 🚿 Regular watering
Oct 6.5" 0.8" 5.7" 🚿 Regular watering
Nov 6.5" 2.1" 4.4" 🚿 Regular watering
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Santa Barbara 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 ~1,089 GDD — county provides 4,522 GDD Excellent fit

Napa Cabbage Planting Timeline — Santa Barbara County, CA

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors February 28 Feb 28 – Mar 14
Direct Sow February 7 Feb 7 – Feb 28
Harvest April 25 Apr 25 – May 30
Fall Sowing September 29 Sep 29 – Oct 13

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

Month-by-Month Timeline

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

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 10a

📆 Growing Season

269 days in Santa Barbara County

Growing Tips for Napa Cabbage in Santa Barbara County

Direct sow Napa Cabbage outdoors after February 28 in Santa Barbara County when soil has warmed and frost danger has passed.

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.

Santa Barbara County receives only 20" 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 Santa Barbara County, CA?

Santa Barbara County is in Zone 10a with an average last frost of February 28. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Santa Barbara County, CA?

Santa Barbara County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 28 and first fall frost is November 24.

🌱

Your Santa Barbara County Garden Planner — Free

A 24-page printable planner built for Santa Barbara County (Zone 10a). 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 Santa Barbara County, CA. 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.