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When to Plant Lavender in Terrebonne Parish, LA

Terrebonne Parish, Louisiana Zone 9b May

May to-do list for Terrebonne Parish, Louisiana

Your Terrebonne Parish, Louisiana garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 7
Avg. first frost December 8
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: lavender

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

To set up a strong June, finish these tasks
  • First harvests: lavender

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Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Terrebonne Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 7 and the first fall frost is December 8, giving you a growing season of approximately 304 days.

At an elevation of 484 feet, Terrebonne Parish receives approximately 61.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Lavender may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lavender will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lavender root diseases.

Terrebonne Parish, LA (Zone 9b) Year-round
304 days
Last Spring Frost February 7
304 growing days
First Fall Frost December 8
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Terrebonne Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.1-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Transplant: Feb 1 🍅 Harvest: May 3 – Oct 4
Recommended (50%) ✓ Fits season (52 days to spare)
Transplant: Feb 14 🍅 Harvest: May 16 – Oct 17
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: Mar 15 🍅 Harvest: Jun 14 – Nov 15

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 Terrebonne Parish

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

Soil pH

Your soil pH (5.1–6.4) is more acidic than Lavender prefers (6.5–8.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Lavender prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is low (2.0%). Add 2-3 inches of compost before planting Lavender.

How to Plant Lavender

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

Plant Water Budget

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

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan 5.3" 0" ❄️ Dormant
Feb 1.3" 5.5" 0" ✅ Rainfall sufficient
Mar 1.3" 6.1" 0" ✅ Rainfall sufficient
Apr 1.3" 5" 0" ✅ Rainfall sufficient
May 1.3" 5" 0" ✅ Rainfall sufficient
Jun 1.3" 5.3" 0" ✅ Rainfall sufficient
Jul 1.3" 6.2" 0" ✅ Rainfall sufficient
Aug 1.3" 5.7" 0" ✅ Rainfall sufficient
Sep 1.3" 4.1" 0" ✅ Rainfall sufficient
Oct 1.3" 3.7" 0" ✅ Rainfall sufficient
Nov 1.3" 4.9" 0" ✅ Rainfall sufficient
Dec 1.3" 5.1" 0" ✅ Rainfall sufficient

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

Lavender 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.

Lavender needs ~3,842 GDD — county provides 8,082 GDD Excellent fit

Lavender Planting Timeline — Terrebonne Parish, LA

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors February 14 Feb 14 – Feb 28
Harvest May 16 May 16 – Oct 17

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–200 days

🧪 Soil pH

Needs 6.5–8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

304 days in Terrebonne Parish

Growing Tips for Lavender in Terrebonne Parish

Direct sow Lavender outdoors after February 07 in Terrebonne Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 102°F in Terrebonne Parish, provide afternoon shade for Lavender and water deeply in the morning.

With 62" of annual rainfall in Terrebonne Parish, ensure good drainage for Lavender — excess moisture can promote root rot and fungal diseases.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Terrebonne Parish, LA?

Terrebonne Parish is in Zone 9b with an average last frost of February 7. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Terrebonne Parish, LA?

Terrebonne Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 7 and first fall frost is December 8.

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Your Terrebonne Parish Garden Planner — Free

A 24-page printable planner built for Terrebonne 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 Terrebonne 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.