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When to Plant Sweet Potatoes in Terrebonne Parish, LA

Terrebonne Parish, Louisiana Zone 9b May

Terrebonne Parish, Louisiana gardeners: here's your May plan

Here's what deserves your attention in Terrebonne Parish, Louisiana this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

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: sweet potatoes

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

June will be here before you know it — start on
  • First harvests: sweet potatoes

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

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 Sweet Potatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Potatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

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

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 (164 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: May 3 – Jun 21
Recommended (50%) ✓ Fits season (157 days to spare)
Start indoors: Dec 27 Transplant: Feb 14 🍅 Harvest: May 16 – Jul 4
Safe Start (90%) ✓ Fits season (142 days to spare)
Start indoors: Jan 25 Transplant: Mar 15 🍅 Harvest: Jun 14 – Aug 2

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 Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (5.1–6.4) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

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

How to Plant Sweet Potatoes

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

Plant Water Budget

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

Monthly Watering Guide for Sweet Potatoes

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

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 5.3" 0" ❄️ Dormant
Feb 4.3" 5.5" 0" ✅ Rainfall sufficient
Mar 4.3" 6.1" 0" ✅ Rainfall sufficient
Apr 4.3" 5" 0" ✅ Rainfall sufficient
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 6.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 4.9" 0" ✅ Rainfall sufficient
Dec 4.3" 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.

Sweet Potatoes 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.

Sweet Potatoes needs ~2,782 GDD — county provides 8,082 GDD Excellent fit

Sweet Potatoes Planting Timeline — Terrebonne Parish, LA

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors December 27 Dec 27 – Jan 10
Transplant Outdoors February 14 Feb 14 – Feb 28
Direct Sow February 7 Feb 7 – Feb 28
Harvest May 16 May 16 – Jul 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

304 days in Terrebonne Parish

Growing Tips for Sweet Potatoes in Terrebonne Parish

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

Sandy soil in Terrebonne Parish dries quickly — mulch Sweet Potatoes 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 Sweet Potatoes and water deeply in the morning.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Terrebonne Parish, LA?

Terrebonne Parish is in Zone 9b with an average last frost of February 7. Plan your Sweet Potatoes 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.

🌱

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.