When to Plant Jicama in Karnes County, TX
Your May gardening checklist
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Karnes County, Texas.
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.
Karnes County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 30, giving you a growing season of approximately 277 days.
At an elevation of 4,532 feet, Karnes County receives approximately 67.2 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Jicama may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Jicama root diseases.
Karnes County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Karnes County
How your county's soil matches Jicama's growing requirements.
Soil pH
Your soil pH (6.3–7.8) overlaps with Jicama's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Karnes County is excellent for Jicama — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Jicama.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Jicama.
How to Plant Jicama
Plant Water Budget
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 | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Mar | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 6.3" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 11.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 9.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Karnes 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 Planting Timeline — Karnes County, TX
Jicama Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 15 | Jan 15 – Jan 29 |
| Transplant Outdoors | March 5 | Mar 5 – Mar 19 |
| Direct Sow | February 26 | Feb 26 – Mar 19 |
| Harvest | July 9 | Jul 9 – Sep 17 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
120–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
277 days in Karnes County
Growing Tips for Jicama in Karnes County
Direct sow Jicama outdoors after February 26 in Karnes 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
Check more plant combinations with our Companion Planting Checker →
Jicama in Other Locations
Frequently Asked Questions
When should I plant Jicama in Karnes County, TX?
Karnes County is in Zone 9a with an average last frost of February 26. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.
What planting zone is Karnes County, TX?
Karnes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 30.
Your Karnes County Garden Planner — Free
A 24-page printable planner built for Karnes County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.