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When to Plant Napa Cabbage in Caldwell County, TX

Caldwell County, Texas Zone 9a May

May in Caldwell County, Texas — your action list

Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 27
Avg. first frost December 1
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting napa cabbage

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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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.

Caldwell County, Texas is in USDA Zone 9a. The average last spring frost is February 27 and the first fall frost is December 1, giving you a growing season of approximately 277 days.

At an elevation of 3,482 feet, Caldwell County receives approximately 60.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Napa Cabbage during the growing season. Clay soil retains moisture well for Napa Cabbage, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Napa Cabbage root diseases.

Caldwell County, TX (Zone 9a) Year-round
277 days
Last Spring Frost February 27
277 growing days
First Fall Frost December 1
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Caldwell County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (188 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: Apr 10 – May 15
Recommended (50%) ✓ Fits season (186 days to spare)
Start indoors: Jan 30 Transplant: Feb 27 🍅 Harvest: Apr 24 – May 29
Safe Start (90%) ✓ Fits season (175 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 17 – Jun 21

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 Caldwell County

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

Soil pH

Your soil pH (6.8–8.1) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

Heavy clay soil (43% clay) in Caldwell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). 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 277-day season

Sow every 6.3 weeks. Last sowing by Sep 17 to harvest before frost.

For a dedicated fall crop, sow by Oct 06.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,726 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.4" 0" ❄️ Dormant
Feb 6.5" 2.1" 4.4" 🚿 Regular watering
Mar 6.5" 4.1" 2.4" 💧 Light watering
Apr 6.5" 6" 0.5" 💧 Light watering
May 6.5" 9.9" 0" ✅ Rainfall sufficient
Jun 6.5" 9.2" 0" ✅ Rainfall sufficient
Jul 6.5" 7.5" 0" ✅ Rainfall sufficient
Aug 6.5" 7.9" 0" ✅ Rainfall sufficient
Sep 6.5" 5.6" 0.9" 💧 Light watering
Oct 6.5" 3.8" 2.7" 💧 Light watering
Nov 6.5" 1.8" 4.7" 🚿 Regular watering
Dec 6.5" 1.5" 5" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Caldwell 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 ~1,138 GDD — county provides 4,865 GDD Excellent fit

Napa Cabbage Planting Timeline — Caldwell County, TX

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 – Feb 13
Transplant Outdoors February 27 Feb 27 – Mar 13
Direct Sow February 6 Feb 6 – Feb 27
Harvest April 24 Apr 24 – May 29
Fall Sowing October 6 Oct 6 – Oct 20

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
October Fall Sowing
November
December
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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 9a

📆 Growing Season

277 days in Caldwell County

Growing Tips for Napa Cabbage in Caldwell County

Direct sow Napa Cabbage outdoors after February 27 in Caldwell County when soil has warmed and frost danger has passed.

With Caldwell County's clay soil (43% clay), work in 3-4 inches of compost before planting Napa Cabbage. Avoid tilling when soil is wet to prevent compaction.

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 Caldwell County, TX?

Caldwell County is in Zone 9a with an average last frost of February 27. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caldwell County, TX?

Caldwell County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 27 and first fall frost is December 1.

🌱

Your Caldwell County Garden Planner — Free

A 24-page printable planner built for Caldwell County (Zone 9a). 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 Caldwell 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.