Blog

When to Plant Napa Cabbage in Galveston County, TX

Galveston County, Texas Zone 9b May

Your May game plan for Galveston County, Texas

May is a pivotal month for Galveston County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 5
Avg. first frost December 7
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for napa cabbage

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

Instant PDF download. No spam, unsubscribe any time.

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.

Galveston County, Texas is in USDA Zone 9b. The average last spring frost is February 5 and the first fall frost is December 7, giving you a growing season of approximately 305 days.

At an elevation of 9 feet, Galveston County receives approximately 72.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Napa Cabbage root diseases.

Galveston County, TX (Zone 9b) Year-round
305 days
Last Spring Frost February 5
305 growing days
First Fall Frost December 7

Galveston County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (226 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Mar 15 – Apr 19
Recommended (50%) ✓ Fits season (214 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🍅 Harvest: Apr 2 – May 7
Safe Start (90%) ✓ Fits season (201 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: May 1 – Jun 5

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 Galveston County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). 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

6
successive plantings in your 305-day season

Sow every 6.3 weeks. Last sowing by Sep 23 to harvest before frost.

For a dedicated fall crop, sow by Oct 12.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,375 gal / 100 sq ft

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 2.1" 0" ❄️ Dormant
Feb 6.5" 2.2" 4.3" 🚿 Regular watering
Mar 6.5" 5.4" 1.1" 💧 Light watering
Apr 6.5" 8.2" 0" ✅ Rainfall sufficient
May 6.5" 10.4" 0" ✅ Rainfall sufficient
Jun 6.5" 10.9" 0" ✅ Rainfall sufficient
Jul 6.5" 8.7" 0" ✅ Rainfall sufficient
Aug 6.5" 8.6" 0" ✅ Rainfall sufficient
Sep 6.5" 6.2" 0.3" 💧 Light watering
Oct 6.5" 5.2" 1.3" 💧 Light watering
Nov 6.5" 2.6" 3.9" 🚿 Regular watering
Dec 6.5" 1.9" 4.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Galveston 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 ~1,625 GDD — county provides 7,650 GDD Excellent fit

Napa Cabbage Planting Timeline — Galveston County, TX

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors January 8 Jan 8 – Jan 22
Transplant Outdoors February 5 Feb 5 – Feb 19
Direct Sow January 15 Jan 15 – Feb 5
Harvest April 2 Apr 2 – May 7
Fall Sowing October 12 Oct 12 – Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

305 days in Galveston County

Growing Tips for Napa Cabbage in Galveston County

Direct sow Napa Cabbage outdoors after February 05 in Galveston County when soil has warmed and frost danger has passed.

Sandy soil in Galveston 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.

With summer highs reaching 100°F in Galveston County, provide afternoon shade for Napa Cabbage and water deeply in the morning.

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.

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 Galveston County, TX?

Galveston County is in Zone 9b with an average last frost of February 5. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Galveston County, TX?

Galveston County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 5 and first fall frost is December 7.

🌱

Your Galveston County Garden Planner — Free

A 24-page printable planner built for Galveston County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Galveston County, TX. 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.