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When to Plant Jicama in Williamson 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.

Williamson County, Texas is in USDA Zone 8b. The average last spring frost is March 5 and the first fall frost is November 22, giving you a growing season of approximately 262 days.

At an elevation of 1,023 feet, Williamson County receives approximately 53.3 inches of rainfall annually with predominantly clay soil. Summer highs average 94ยฐF, providing good warmth for Jicama during the growing season. Clay soil retains moisture well for Jicama, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Jicama root diseases.

Williamson County, TX (Zone 8b) Long season
262 days
Last Spring Frost March 5
262 growing days
First Fall Frost November 22

Williamson County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Jan 3 Transplant: Mar 7 🍅 Harvest: Jul 11 – Sep 19
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: Jul 23 – Oct 1
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Aug 24 – Nov 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.

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
Jicama needs ~3,075 GDD — county provides 5,371 GDD Excellent fit

Jicama Planting Timeline โ€” Williamson County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 โ€“ Jan 29
Transplant Outdoors March 19 Mar 19 โ€“ Apr 2
Direct Sow March 12 Mar 12 โ€“ Apr 2
Harvest July 23 Jul 23 โ€“ Oct 1

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February โ€”
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

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

120โ€“180 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8b

Growing Season

262 days

Growing Tips for Williamson County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Jicama in Williamson County, TX?

Williamson County is in Zone 8b with an average last frost of March 5. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Williamson County, TX?

Williamson County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 5 and first fall frost is November 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Williamson County gardeners in Zone 8b 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 Williamson County, TX. Local conditions may vary. Last updated: April 2026.