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When to Plant Jicama in Blanco County, TX

Blanco County, Texas Zone 8b May

Your May game plan for Blanco County, Texas

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 8
Avg. first frost November 21
Soil temp (4") 61°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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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.

Blanco County, Texas is in USDA Zone 8b. The average last spring frost is March 8 and the first fall frost is November 21, giving you a growing season of approximately 258 days.

At an elevation of 4,826 feet, Blanco County receives approximately 61.5 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, 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.

Blanco County, TX (Zone 8b) Long season
258 days
Last Spring Frost March 8
258 growing days
First Fall Frost November 21

Blanco County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Jan 11 Transplant: Mar 15 🍅 Harvest: Jul 19 – Sep 27
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Jan 18 Transplant: Mar 22 🍅 Harvest: Jul 26 – Oct 4
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Aug 25 – Nov 3

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 Blanco County

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

Soil pH

Your soil pH (7.1–7.7) overlaps with Jicama's range (6.0–7.5), though not a perfect match.

Soil Texture

Your clay soil in Blanco County is workable for Jicama. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (3.1%). 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
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 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 10.3" 0" ✅ Rainfall sufficient
Jun 4.3" 9.9" 0" ✅ Rainfall sufficient
Jul 4.3" 7.7" 0" ✅ Rainfall sufficient
Aug 4.3" 6.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.4" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Blanco 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 ~2,625 GDD — county provides 4,515 GDD Excellent fit

Jicama Planting Timeline — Blanco County, TX

Jicama Planting Calendar

Activity When Date Range
Start Indoors January 18 Jan 18 – Feb 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 15 Mar 15 – Apr 5
Harvest July 26 Jul 26 – Oct 4

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8b

📆 Growing Season

258 days in Blanco County

Growing Tips for Jicama in Blanco County

Direct sow Jicama outdoors after March 08 in Blanco County when soil has warmed and frost danger has passed.

With Blanco County's clay soil (36% 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 Blanco County, TX?

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

What planting zone is Blanco County, TX?

Blanco County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 8 and first fall frost is November 21.

🌱

Your Blanco County Garden Planner — Free

A 24-page printable planner built for Blanco County (Zone 8b). 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 Blanco 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.