When to Plant Jicama in Lamar 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.
Lamar County, Texas is in USDA Zone 7b. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.
At an elevation of 95 feet, Lamar County receives approximately 59.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°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.
Lamar County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.8-6.8
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 Lamar County
How your county's soil matches Jicama's growing requirements.
Soil pH
Your soil pH (5.8–6.8) overlaps with Jicama's range (6.0–7.5), though not a perfect match.
Soil Texture
Sandy soil in Lamar 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 (1.9%). Add 2-3 inches of compost before planting 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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 2.1" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Apr | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.8" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 9.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Lamar 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 — Lamar County, TX
Jicama Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 25 | Jan 25 – Feb 8 |
| Transplant Outdoors | March 29 | Mar 29 – Apr 12 |
| Direct Sow | March 22 | Mar 22 – Apr 12 |
| Harvest | August 2 | Aug 2 – Oct 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | — |
| 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 7b
📆 Growing Season
245 days in Lamar County
Growing Tips for Jicama in Lamar County
Direct sow Jicama outdoors after March 15 in Lamar County when soil has warmed and frost danger has passed.
Sandy soil in Lamar County dries quickly — mulch Jicama with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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
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Check more plant combinations with our Companion Planting Checker →
Jicama in Other Locations
Frequently Asked Questions
When should I plant Jicama in Lamar County, TX?
Lamar County is in Zone 7b with an average last frost of March 15. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lamar County, TX?
Lamar County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 15 and first fall frost is November 15.
Plan Your Garden with Confidence
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