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When to Plant Jicama in Oldham County, TX

Oldham County, Texas Zone 7a May

May in the garden — Oldham County, Texas

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oldham County, Texas.

Avg. last frost April 19
Avg. first frost October 18
Soil temp (4") 64°F
Watering High
Pest pressure Moderate
Daylight 13.9 hrs
  1. Time to transplant jicama

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

Coming up in June — start thinking about
  • Starting indoors: jicama

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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.

Oldham County, Texas is in USDA Zone 7a. The average last spring frost is April 19 and the first fall frost is October 18, giving you a growing season of approximately 182 days.

At an elevation of 2,350 feet, Oldham County receives approximately 56 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Jicama during the growing season. Sandy soil warms quickly in spring — great for early planting — 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.

Oldham County, TX (Zone 7a) Moderate season
182 days
Last Spring Frost April 19
182 growing days
First Fall Frost October 18

Oldham County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Sep 1 – Nov 10
Recommended (50%) ✗ May not fit
Start indoors: Mar 1 Transplant: May 3 🍅 Harvest: Sep 6 – Nov 15
Safe Start (90%) ✗ May not fit
Start indoors: Mar 15 Transplant: May 17 🍅 Harvest: Sep 20 – Nov 29

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 Oldham County

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

Soil pH

Your soil pH (7.2–8.3) is more alkaline than Jicama prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Oldham 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 low (0.9%). Add 2-3 inches of compost before planting 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
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 3.4" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 4.3" 1.8" 2.5" 🚿 Regular watering
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 10.4" 0" ✅ Rainfall sufficient
Aug 4.3" 12.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.7" 0" ✅ Rainfall sufficient
Nov 3.1" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Oldham County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~3,075 GDD — county provides 3,731 GDD Good fit

Jicama Planting Timeline — Oldham County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 3 May 3 – May 17
Direct Sow April 26 Apr 26 – May 17
Harvest September 6 Sep 6 – Nov 15

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

182 days in Oldham County

Growing Tips for Jicama in Oldham County

Direct sow Jicama outdoors after April 19 in Oldham County when soil has warmed and frost danger has passed.

Sandy soil in Oldham County dries quickly — mulch Jicama with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your 182.0-day growing season in Oldham County is tight for Jicama (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Oldham County, TX?

Oldham County is in Zone 7a with an average last frost of April 19. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oldham County, TX?

Oldham County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 19 and first fall frost is October 18.

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Your Oldham County Garden Planner — Free

A 24-page printable planner built for Oldham County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Oldham County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.