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When to Plant Jicama in Jack 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.

Jack County, Texas is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.

At an elevation of 2,081 feet, Jack County receives approximately 66.9 inches of rainfall annually with predominantly clay soil. Summer highs average 89ยฐF, 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.

Jack County, TX (Zone 7b) Long season
228 days
Last Spring Frost March 26
228 growing days
First Fall Frost November 9

Jack County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Jan 29 Transplant: Apr 2 🍅 Harvest: Aug 6 – Oct 15
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🍅 Harvest: Aug 13 – Oct 22
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Sep 3 – Nov 12

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 Jack County

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

Soil pH

Your soil pH (7.3โ€“7.6) overlaps with Jicama's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

Heavy clay soil (42% clay) in Jack County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Drainage

Drainage is adequate for Jicama.

Organic Matter

Organic matter is moderate (3.2%). 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
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€” 2" 0" โ„๏ธ Dormant
Feb โ€” 2.3" 0" โ„๏ธ Dormant
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 8" 0" โœ… Rainfall sufficient
May 4.3" 9.7" 0" โœ… Rainfall sufficient
Jun 4.3" 9.6" 0" โœ… Rainfall sufficient
Jul 4.3" 8.5" 0" โœ… Rainfall sufficient
Aug 4.3" 7.6" 0" โœ… Rainfall sufficient
Sep 4.3" 6.7" 0" โœ… Rainfall sufficient
Oct 4.3" 4.3" 0" โœ… Rainfall sufficient
Nov 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Dec โ€” 1.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Jack 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 ~2,512 GDD — county provides 3,819 GDD Excellent fit

Jicama Planting Timeline โ€” Jack County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 โ€“ Feb 19
Transplant Outdoors April 9 Apr 9 โ€“ Apr 23
Direct Sow April 2 Apr 2 โ€“ Apr 23
Harvest August 13 Aug 13 โ€“ Oct 22

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March โ€”
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July โ€”
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 7b

๐Ÿ“† Growing Season

228 days in Jack County

Growing Tips for Jicama in Jack County

Direct sow Jicama outdoors after March 26 in Jack County when soil has warmed and frost danger has passed.

With Jack County's clay soil (42% clay), work in 3-4 inches of compost before planting Jicama. Avoid tilling when soil is wet to prevent compaction.

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 Jack County, TX?

Jack County is in Zone 7b with an average last frost of March 26. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jack County, TX?

Jack County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jack County gardeners in Zone 7b 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 Jack County, TX. Local conditions may vary. Last updated: April 2026.