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When to Plant Jicama in Willacy 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.

Willacy County, Texas is in USDA Zone 9b. The average last spring frost is February 4 and the first fall frost is December 22, giving you a growing season of approximately 321 days.

At an elevation of 1,085 feet, Willacy County receives approximately 65.9 inches of rainfall annually with predominantly loam soil. Summer highs average 102ยฐF, so Jicama may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Jicama root diseases.

Willacy County, TX (Zone 9b) Year-round
321 days
Last Spring Frost February 4
321 growing days
First Fall Frost December 22

Willacy County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (130 days to spare)
Start indoors: Dec 6 Transplant: Jan 24 🍅 Harvest: May 30 – Aug 8
Recommended (50%) ✓ Fits season (118 days to spare)
Start indoors: Dec 24 Transplant: Feb 11 🍅 Harvest: Jun 17 – Aug 26
Safe Start (90%) ✓ Fits season (95 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🍅 Harvest: Jul 15 – Sep 23

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 Willacy County

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

Soil pH

Your soil pH (6.5โ€“7.3) is within Jicama's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Willacy County is excellent for Jicama โ€” good drainage, moisture retention, and nutrient holding capacity.

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
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,515 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.7" 0" โ„๏ธ Dormant
Feb 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Mar 4.3" 4.4" 0" โœ… Rainfall sufficient
Apr 4.3" 6.4" 0" โœ… Rainfall sufficient
May 4.3" 9.5" 0" โœ… Rainfall sufficient
Jun 4.3" 9.7" 0" โœ… Rainfall sufficient
Jul 4.3" 9" 0" โœ… Rainfall sufficient
Aug 4.3" 8.5" 0" โœ… Rainfall sufficient
Sep 4.3" 6.3" 0" โœ… Rainfall sufficient
Oct 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Nov 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Dec 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Willacy 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 ~3,975 GDD — county provides 8,533 GDD Excellent fit

Jicama Planting Timeline โ€” Willacy County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors December 24 Dec 24 โ€“ Jan 7
Transplant Outdoors February 11 Feb 11 โ€“ Feb 25
Direct Sow February 4 Feb 4 โ€“ Feb 25
Harvest June 17 Jun 17 โ€“ Aug 26

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

321 days in Willacy County

Growing Tips for Jicama in Willacy County

Direct sow Jicama outdoors after February 04 in Willacy County when soil has warmed and frost danger has passed.

With summer highs reaching 102ยฐF in Willacy County, 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 Willacy County, TX?

Willacy County is in Zone 9b with an average last frost of February 4. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Willacy County, TX?

Willacy County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 4 and first fall frost is December 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Willacy County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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