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When to Plant Jicama in Mills 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.

Mills County, Texas is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 12, giving you a growing season of approximately 234 days.

At an elevation of 4,208 feet, Mills County receives approximately 61.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Jicama during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Jicama root diseases.

Mills County, TX (Zone 8a) Long season
234 days
Last Spring Frost March 23
234 growing days
First Fall Frost November 12

Mills County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (27 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jul 30 – Oct 8
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Aug 10 – Oct 19
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Sep 1 – Nov 10

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 Mills County

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

Soil pH

Your soil pH (6.7โ€“7.6) overlaps with Jicama's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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
1.1″/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€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 2.4" 0" โ„๏ธ Dormant
Mar 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Apr 4.3" 6.2" 0" โœ… Rainfall sufficient
May 4.3" 10.5" 0" โœ… Rainfall sufficient
Jun 4.3" 9.5" 0" โœ… Rainfall sufficient
Jul 4.3" 7.5" 0" โœ… Rainfall sufficient
Aug 4.3" 7" 0" โœ… Rainfall sufficient
Sep 4.3" 5.6" 0" โœ… Rainfall sufficient
Oct 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Nov 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Mills 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 ~2,625 GDD — county provides 4,095 GDD Excellent fit

Jicama Planting Timeline โ€” Mills County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 โ€“ Feb 16
Transplant Outdoors April 6 Apr 6 โ€“ Apr 20
Direct Sow March 30 Mar 30 โ€“ Apr 20
Harvest August 10 Aug 10 โ€“ Oct 19

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Direct Sow
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 8a

๐Ÿ“† Growing Season

234 days in Mills County

Growing Tips for Jicama in Mills County

Direct sow Jicama outdoors after March 23 in Mills County when soil has warmed and frost danger has passed.

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 Mills County, TX?

Mills County is in Zone 8a with an average last frost of March 23. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mills County, TX?

Mills County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mills 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 Mills County, TX. Local conditions may vary. Last updated: April 2026.