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When to Plant Kai Lan in St. Bernard Parish, LA

St. Bernard Parish, Louisiana Zone 9b May

St. Bernard Parish, Louisiana gardeners: here's your May plan

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

Avg. last frost February 2
Avg. first frost December 11
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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Kai lan (Chinese broccoli) is a brassica grown for its thick, glossy stems and small flower buds. It has a slightly bitter, broccoli-like flavor essential in Cantonese cooking.

St. Bernard Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 2 and the first fall frost is December 11, giving you a growing season of approximately 312 days.

At an elevation of 455 feet, St. Bernard Parish receives approximately 51.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 104°F, so Kai Lan may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kai Lan will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kai Lan root diseases.

St. Bernard Parish, LA (Zone 9b) Year-round
312 days
Last Spring Frost February 2
312 growing days
First Fall Frost December 11
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St. Bernard Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (241 days to spare)
Start indoors: Dec 25 Transplant: Jan 22 🍅 Harvest: Mar 12 – Apr 9
Recommended (50%) ✓ Fits season (235 days to spare)
Start indoors: Jan 5 Transplant: Feb 2 🍅 Harvest: Mar 23 – Apr 20
Safe Start (90%) ✓ Fits season (218 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 23 – May 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 St. Bernard Parish

How your county's soil matches Kai Lan's growing requirements.

Soil pH

Your soil pH (5.2–6.5) is more acidic than Kai Lan prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Kai Lan.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help Kai Lan.

How to Plant Kai Lan

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Kai Lan

8
successive plantings in your 312-day season

Sow every 5.1 weeks. Last sowing by Oct 12 to harvest before frost.

For a dedicated fall crop, sow by Oct 16.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 17 gal / 100 sq ft

Monthly Watering Guide for Kai Lan

Kai Lan needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Kai Lan Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 4.3" 4.4" 0" ✅ Rainfall sufficient
Mar 4.3" 5.3" 0" ✅ Rainfall sufficient
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 5.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 4.3" 3.5" 0.8" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in St. Bernard Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kai Lan 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.

Kai Lan needs ~1,470 GDD — county provides 8,764 GDD Excellent fit

Kai Lan Planting Timeline — St. Bernard Parish, LA

Kai Lan Planting Calendar

Activity When Date Range
Start Indoors January 5 Jan 5 – Jan 19
Transplant Outdoors February 2 Feb 2 – Feb 16
Direct Sow January 12 Jan 12 – Feb 2
Harvest March 23 Mar 23 – Apr 20
Fall Sowing October 16 Oct 16 – Oct 30

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

312 days in St. Bernard Parish

Growing Tips for Kai Lan in St. Bernard Parish

Direct sow Kai Lan outdoors after February 02 in St. Bernard Parish when soil has warmed and frost danger has passed.

Sandy soil in St. Bernard Parish dries quickly — mulch Kai Lan with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 104°F in St. Bernard Parish, provide afternoon shade for Kai Lan and water deeply in the morning.

Your generous 313.0-day season in St. Bernard Parish allows multiple plantings of Kai Lan. Sow every 22.0 days for continuous harvest.

Common pests for Kai Lan in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest when flower buds first appear but before they open. Cut stems at the base to encourage side shoots. Prefers cool weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kai Lan in St. Bernard Parish, LA?

St. Bernard Parish is in Zone 9b with an average last frost of February 2. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Bernard Parish, LA?

St. Bernard Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 2 and first fall frost is December 11.

🌱

Your St. Bernard Parish Garden Planner — Free

A 24-page printable planner built for St. Bernard Parish (Zone 9b). 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 St. Bernard 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.