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When to Plant Yam in Plaquemines Parish, LA

Plaquemines Parish, Louisiana Zone 9b May

This month in Plaquemines Parish, Louisiana

Your Plaquemines 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 6
Avg. first frost December 7
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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True yams are tropical tubers distinct from sweet potatoes, producing large starchy roots that can weigh several pounds. They are a staple food in tropical regions worldwide.

Plaquemines Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 6 and the first fall frost is December 7, giving you a growing season of approximately 304 days.

At an elevation of 386 feet, Plaquemines Parish receives approximately 50.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99°F, so Yam may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Yam will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yam root diseases.

Plaquemines Parish, LA (Zone 9b) Year-round
304 days
Last Spring Frost February 6
304 growing days
First Fall Frost December 7

Plaquemines Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Aug 2 – Nov 29
Recommended (50%) ✗ May not fit
Start indoors: Dec 26 Transplant: Feb 13 🍅 Harvest: Aug 14 – Dec 11
Safe Start (90%) ✓ Fits season (346 days to spare)
Start indoors: Jan 26 Transplant: Mar 16 🍅 Harvest: Sep 14 – Jan 11

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 Plaquemines Parish

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

Soil pH

Your soil pH (4.8–6.0) is more acidic than Yam prefers (5.5–6.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

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

How to Plant Yam

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,006 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Yam

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

Month Yam Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 4.3" 3.5" 0.8" 💧 Light watering
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.9" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 3.7" 0.6" 💧 Light watering
Dec 4.3" 4.5" 0" ✅ Rainfall sufficient

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

Yam 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.

Yam needs ~6,184 GDD — county provides 7,396 GDD Good fit

Yam Planting Timeline — Plaquemines Parish, LA

Yam Planting Calendar

Activity When Date Range
Start Indoors December 26 Dec 26 – Jan 9
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow February 6 Feb 6 – Feb 27
Harvest August 14 Aug 14 – Dec 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

180–330 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

304 days in Plaquemines Parish

Growing Tips for Yam in Plaquemines Parish

Direct sow Yam outdoors after February 06 in Plaquemines Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in Plaquemines Parish, provide afternoon shade for Yam and water deeply in the morning.

Your 305.0-day growing season in Plaquemines Parish is tight for Yam (180.0-330.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant tuber pieces in mounds of loose, rich soil. Provide sturdy trellising for climbing vines. Yams require a long, warm growing season of 8-11 months. Harvest when vines die back.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yam in Plaquemines Parish, LA?

Plaquemines Parish is in Zone 9b with an average last frost of February 6. Plan your Yam planting based on this frost date — see the calendar above for exact timing.

What planting zone is Plaquemines Parish, LA?

Plaquemines Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 6 and first fall frost is December 7.

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Your Plaquemines Parish Garden Planner — Free

A 24-page printable planner built for Plaquemines 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 Plaquemines 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.