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When to Plant Jicama in Harris 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.

Harris County, Texas is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.

At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102ยฐF, so Jicama may need afternoon shade and extra watering during peak heat. 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.

Harris County, TX (Zone 9a) Year-round
293 days
Last Spring Frost February 14
293 growing days
First Fall Frost December 4

Harris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Dec 26 Transplant: Feb 13 🍅 Harvest: Jun 19 – Aug 28
Recommended (50%) ✓ Fits season (90 days to spare)
Start indoors: Jan 3 Transplant: Feb 21 🍅 Harvest: Jun 27 – Sep 5
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Jan 25 Transplant: Mar 15 🍅 Harvest: Jul 19 – Sep 27

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 Harris County

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

Soil pH

Your soil pH (5.3โ€“6.5) is more acidic than Jicama prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Harris 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 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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 86 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€” 1.6" 0" โ„๏ธ Dormant
Feb 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Mar 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Apr 4.3" 7.4" 0" โœ… Rainfall sufficient
May 4.3" 10.1" 0" โœ… Rainfall sufficient
Jun 4.3" 10" 0" โœ… Rainfall sufficient
Jul 4.3" 9.6" 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" 3.9" 0.4" ๐Ÿ’ง Light watering
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Harris 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 7,791 GDD Excellent fit

Jicama Planting Timeline โ€” Harris County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors January 3 Jan 3 โ€“ Jan 17
Transplant Outdoors February 21 Feb 21 โ€“ Mar 7
Direct Sow February 14 Feb 14 โ€“ Mar 7
Harvest June 27 Jun 27 โ€“ Sep 5

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 Transplant Outdoors Direct Sow
April โ€”
May โ€”
June Harvest
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

293 days in Harris County

Growing Tips for Jicama in Harris County

Direct sow Jicama outdoors after February 14 in Harris County when soil has warmed and frost danger has passed.

Sandy soil in Harris 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.

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

Harris County is in Zone 9a with an average last frost of February 14. Plan your Jicama planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harris County, TX?

Harris County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harris County gardeners in Zone 9a 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 Harris County, TX. Local conditions may vary. Last updated: April 2026.