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When to Plant Jicama in Marion County, TX

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.

Marion County, Texas is in USDA Zone 8a. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.

At an elevation of 393 feet, Marion County receives approximately 72 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 93ยฐF, providing good warmth for Jicama during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Marion County, TX (Zone 8a) Long season
246 days
Last Spring Frost March 13
246 growing days
First Fall Frost November 14

Marion County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: Jul 23 – Oct 1
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: Jul 31 – Oct 9
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Aug 23 – Nov 1

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 Marion County

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

Soil pH

Your soil pH (5.6โ€“6.6) overlaps with Jicama's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

Sandy soil in Marion County warms quickly in spring but drains fast. Jicama will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting 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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 1.9" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar 4.3" 5" 0" โœ… Rainfall sufficient
Apr 4.3" 8.3" 0" โœ… Rainfall sufficient
May 4.3" 9" 0" โœ… Rainfall sufficient
Jun 4.3" 11.2" 0" โœ… Rainfall sufficient
Jul 4.3" 10.1" 0" โœ… Rainfall sufficient
Aug 4.3" 7.7" 0" โœ… Rainfall sufficient
Sep 4.3" 7.1" 0" โœ… Rainfall sufficient
Oct 4.3" 5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Dec โ€” 1.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Marion County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,962 GDD — county provides 4,858 GDD Excellent fit

Jicama Planting Timeline โ€” Marion County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 โ€“ Feb 6
Transplant Outdoors March 27 Mar 27 โ€“ Apr 10
Direct Sow March 20 Mar 20 โ€“ Apr 10
Harvest July 31 Jul 31 โ€“ Oct 9

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

246 days in Marion County

Growing Tips for Jicama in Marion County

Direct sow Jicama outdoors after March 13 in Marion County when soil has warmed and frost danger has passed.

Sandy soil in Marion County dries quickly โ€” mulch Jicama with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Marion County, TX?

Marion County is in Zone 8a with an average last frost of March 13. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marion County, TX?

Marion County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 13 and first fall frost is November 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marion County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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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 Marion County, TX. Local conditions may vary. Last updated: April 2026.