Blog

When to Plant Napa Cabbage in St. Martin Parish, LA

St. Martin Parish, Louisiana Zone 9a May

May in the garden — St. Martin Parish, Louisiana

Your garden in St. Martin Parish, Louisiana is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 13
Avg. first frost December 5
Soil temp (4") 75°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Pick napa cabbage

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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.

St. Martin Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.

At an elevation of 417 feet, St. Martin Parish receives approximately 55.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°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.

St. Martin Parish, LA (Zone 9a) Year-round
295 days
Last Spring Frost February 13
295 growing days
First Fall Frost December 5

St. Martin Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (208 days to spare)
Start indoors: Jan 3 Transplant: Jan 31 🍅 Harvest: Mar 28 – May 2
Recommended (50%) ✓ Fits season (204 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: Apr 10 – May 15
Safe Start (90%) ✓ Fits season (194 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: May 4 – Jun 8

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 St. Martin Parish

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

Soil pH

Your soil pH (5.2–6.0) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Napa Cabbage.

Organic Matter

Organic matter is moderate (2.3%). 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 295-day season

Sow every 6.3 weeks. Last sowing by Sep 21 to harvest before frost.

For a dedicated fall crop, sow by Oct 10.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 695 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 5.1" 0" ❄️ Dormant
Feb 6.5" 4.4" 2.1" 💧 Light watering
Mar 6.5" 5.7" 0.8" 💧 Light watering
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 3.7" 2.8" 💧 Light watering
Jun 6.5" 5.1" 1.4" 💧 Light watering
Jul 6.5" 6.4" 0.1" 💧 Light watering
Aug 6.5" 5.6" 0.9" 💧 Light watering
Sep 6.5" 3.8" 2.7" 💧 Light watering
Oct 6.5" 3.3" 3.2" 💧 Light watering
Nov 6.5" 4.4" 2.1" 💧 Light watering
Dec 6.5" 4.1" 2.4" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in St. Martin Parish). 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 ~1,430 GDD — county provides 6,512 GDD Excellent fit

Napa Cabbage Planting Timeline — St. Martin Parish, LA

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow January 23 Jan 23 – Feb 13
Harvest April 10 Apr 10 – May 15
Fall Sowing October 10 Oct 10 – Oct 24

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 · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

295 days in St. Martin Parish

Growing Tips for Napa Cabbage in St. Martin Parish

Direct sow Napa Cabbage outdoors after February 13 in St. Martin Parish when soil has warmed and frost danger has passed.

Sandy soil in St. Martin Parish 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 96°F in St. Martin Parish, 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 St. Martin Parish, LA?

St. Martin Parish is in Zone 9a with an average last frost of February 13. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Martin Parish, LA?

St. Martin Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 5.

🌱

Your St. Martin Parish Garden Planner — Free

A 24-page printable planner built for St. Martin Parish (Zone 9a). 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 St. Martin Parish, LA. 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.