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When to Plant Leeks in Lafourche Parish, LA

Lafourche Parish, Louisiana Zone 9b May

May in Lafourche Parish, Louisiana — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Lafourche Parish, Louisiana.

Avg. last frost January 27
Avg. first frost December 18
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Collect leeks at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

June prep starts now
  • First harvests: leeks

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Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Lafourche Parish, Louisiana is in USDA Zone 9b. The average last spring frost is January 27 and the first fall frost is December 18, giving you a growing season of approximately 325 days.

At an elevation of 306 feet, Lafourche Parish receives approximately 54 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Leeks may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Leeks will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

Lafourche Parish, LA (Zone 9b) Year-round
325 days
Last Spring Frost January 27
325 growing days
First Fall Frost December 18
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Lafourche Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (154 days to spare)
Start indoors: Dec 23 Transplant: Jan 20 🍅 Harvest: Apr 21 – Jul 7
Recommended (50%) ✓ Fits season (157 days to spare)
Start indoors: Dec 30 Transplant: Jan 27 🍅 Harvest: Apr 28 – Jul 14
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Jun 3 – Aug 19

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 Lafourche Parish

How your county's soil matches Leeks's growing requirements.

Soil pH

Your soil pH (5.0–6.2) is more acidic than Leeks prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 3.5" 4.3" 0" ✅ Rainfall sufficient
Feb 3.5" 4.5" 0" ✅ Rainfall sufficient
Mar 3.5" 5.2" 0" ✅ Rainfall sufficient
Apr 3.5" 4.2" 0" ✅ Rainfall sufficient
May 3.5" 4.8" 0" ✅ Rainfall sufficient
Jun 3.5" 5.3" 0" ✅ Rainfall sufficient
Jul 3.5" 5.3" 0" ✅ Rainfall sufficient
Aug 3.5" 5.6" 0" ✅ Rainfall sufficient
Sep 3.5" 4.3" 0" ✅ Rainfall sufficient
Oct 3.5" 3.4" 0.1" 💧 Light watering
Nov 3.5" 3.5" 0" ✅ Rainfall sufficient
Dec 3.5" 3.6" 0" ✅ Rainfall sufficient

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

Leeks 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.

Leeks needs ~2,730 GDD — county provides 7,416 GDD Excellent fit

Leeks Planting Timeline — Lafourche Parish, LA

Leeks Planting Calendar

Activity When Date Range
Start Indoors December 30 Dec 30 – Jan 13
Transplant Outdoors January 27 Jan 27 – Feb 10
Direct Sow January 6 Jan 6 – Jan 27
Harvest April 28 Apr 28 – Jul 14
Fall Sowing October 23 Oct 23 – Nov 6

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

325 days in Lafourche Parish

Growing Tips for Leeks in Lafourche Parish

Direct sow Leeks outdoors after January 27 in Lafourche Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 97°F in Lafourche Parish, provide afternoon shade for Leeks and water deeply in the morning.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Lafourche Parish, LA?

Lafourche Parish is in Zone 9b with an average last frost of January 27. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lafourche Parish, LA?

Lafourche Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is January 27 and first fall frost is December 18.

🌱

Your Lafourche Parish Garden Planner — Free

A 24-page printable planner built for Lafourche 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 Lafourche 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.