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When to Plant Lemongrass in St. Bernard Parish, LA

St. Bernard Parish, Louisiana Zone 9a April

What to do in April

If you only do a handful of things in the garden this April, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 2
Avg. first frost December 11
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 12.7 hrs
  1. It's harvest week for lemongrass

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

Before May arrives, get these ready
  • First harvests: lemongrass

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Lemongrass is a tropical grass with a strong citrus aroma used extensively in Southeast Asian cuisine. The swollen stem bases are the most flavorful part.

St. Bernard Parish, Louisiana is in USDA Zone 9a. 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 Lemongrass may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lemongrass will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lemongrass root diseases.

St. Bernard Parish, LA (Zone 9a) 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 (143 days to spare)
Start indoors: Dec 11 Transplant: Jan 29 🍅 Harvest: Apr 16 – Jul 16
Recommended (50%) ✓ Fits season (137 days to spare)
Start indoors: Dec 22 Transplant: Feb 9 🍅 Harvest: Apr 27 – Jul 27
Safe Start (90%) ✓ Fits season (120 days to spare)
Start indoors: Jan 22 Transplant: Mar 12 🍅 Harvest: May 28 – Aug 27

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 Lemongrass's growing requirements.

Soil pH

Your soil pH (5.2–6.5) overlaps with Lemongrass's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lemongrass.

Organic Matter

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

How to Plant Lemongrass

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Lemongrass

4
successive plantings in your 312-day season

Sow every 8.6 weeks. Last sowing by Aug 13 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 992 gal / 100 sq ft

Monthly Watering Guide for Lemongrass

Lemongrass 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 Lemongrass Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 6.5" 4.4" 2.1" 💧 Light watering
Mar 6.5" 5.3" 1.2" 💧 Light watering
Apr 6.5" 4" 2.5" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.8" 1.7" 💧 Light watering
Jul 6.5" 5.9" 0.6" 💧 Light watering
Aug 6.5" 4.2" 2.3" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 6.5" 3.9" 2.6" 💧 Light watering
Dec 6.5" 3.5" 3" 💧 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.

Lemongrass 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.

Lemongrass needs ~2,730 GDD — county provides 8,764 GDD Excellent fit

Lemongrass Planting Timeline — St. Bernard Parish, LA

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors December 22 Dec 22 – Jan 5
Transplant Outdoors February 9 Feb 9 – Feb 23
Direct Sow February 9 Feb 9 – Mar 2
Harvest April 27 Apr 27 – Jul 27

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

75–120 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

312 days in St. Bernard Parish

Growing Tips for Lemongrass in St. Bernard Parish

Direct sow Lemongrass 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 Lemongrass 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 Lemongrass and water deeply in the morning.

Common pests for Lemongrass in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Start from divisions or store-bought stalks rooted in water. Grow in rich, moist soil with full sun. In cold climates, grow in containers and overwinter indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

St. Bernard Parish is in Zone 9a with an average last frost of February 2. Plan your Lemongrass 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 9a. 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 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 St. Bernard Parish, LA. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.