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When to Plant Jicama in St. John the Baptist Parish, LA

St. John the Baptist Parish, Louisiana Zone 9b May

Your May gardening checklist

Each item below is timed to St. John the Baptist Parish, Louisiana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 20
Avg. first frost December 1
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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Jicama is a tropical legume grown for its crisp, sweet, starchy root. It requires a very long, warm growing season but produces a refreshing, water chestnut-like tuber.

St. John the Baptist Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.

At an elevation of 309 feet, St. John the Baptist Parish receives approximately 53.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Jicama may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Jicama will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Jicama root diseases.

St. John the Baptist Parish, LA (Zone 9b) Year-round
284 days
Last Spring Frost February 20
284 growing days
First Fall Frost December 1
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St. John the Baptist Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Dec 26 Transplant: Feb 13 🍅 Harvest: Jun 19 – Aug 28
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Jan 9 Transplant: Feb 27 🍅 Harvest: Jul 3 – Sep 11
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Feb 8 Transplant: Mar 29 🍅 Harvest: Aug 2 – Oct 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 St. John the Baptist Parish

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

Soil pH

Your soil pH (4.8–6.1) is more acidic than Jicama prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Jicama.

Organic Matter

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

How to Plant Jicama

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

Plant Water Budget

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

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

Monthly Watering Guide for Jicama

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

Month Jicama Needs Rainfall You Supplement Action
Jan 4" 0" ❄️ Dormant
Feb 4.3" 4" 0.3" 💧 Light watering
Mar 4.3" 4.6" 0" ✅ Rainfall sufficient
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 6.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 3.5" 0.8" 💧 Light watering
Dec 4.3" 4.8" 0" ✅ Rainfall sufficient

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

Jicama 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.

Jicama needs ~4,088 GDD — county provides 7,766 GDD Excellent fit

Jicama Planting Timeline — St. John the Baptist Parish, LA

Jicama Planting Calendar

Activity When Date Range
Start Indoors January 9 Jan 9 – Jan 23
Transplant Outdoors February 27 Feb 27 – Mar 13
Direct Sow February 20 Feb 20 – Mar 13
Harvest July 3 Jul 3 – Sep 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

284 days in St. John the Baptist Parish

Growing Tips for Jicama in St. John the Baptist Parish

Direct sow Jicama outdoors after February 20 in St. John the Baptist Parish when soil has warmed and frost danger has passed.

Sandy soil in St. John the Baptist Parish dries quickly — mulch Jicama with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 103°F in St. John the Baptist Parish, provide afternoon shade for Jicama and water deeply in the morning.

Common pests for Jicama in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Pinch off flowers to direct energy to root development. Harvest before first frost when roots are 3-6 inches across.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Jicama in St. John the Baptist Parish, LA?

St. John the Baptist Parish is in Zone 9b with an average last frost of February 20. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. John the Baptist Parish, LA?

St. John the Baptist Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is December 1.

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Your St. John the Baptist Parish Garden Planner — Free

A 24-page printable planner built for St. John the Baptist 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 St. John the Baptist 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.