When to Plant Yam in San Patricio County, TX
Your May game plan for San Patricio County, Texas
A quick May briefing for San Patricio County, Texas gardeners — what's urgent, what's next, and what can wait.
True yams are tropical tubers distinct from sweet potatoes, producing large starchy roots that can weigh several pounds. They are a staple food in tropical regions worldwide.
San Patricio County, Texas is in USDA Zone 9b. The average last spring frost is February 12 and the first fall frost is December 9, giving you a growing season of approximately 300 days.
At an elevation of 2,449 feet, San Patricio County receives approximately 54.7 inches of rainfall annually with predominantly loam soil. Summer highs average 100°F, so Yam may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yam root diseases.
San Patricio County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
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 San Patricio County
How your county's soil matches Yam's growing requirements.
Soil pH
Your soil pH (6.8–7.2) is more alkaline than Yam prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in San Patricio County is excellent for Yam — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is low (1.9%). Add 2-3 inches of compost before planting Yam.
How to Plant Yam
Plant Water Budget
Monthly Watering Guide for Yam
Yam needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Yam Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Mar | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Apr | 4.3" | 6.4" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Dec | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in San Patricio County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Yam 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.
Yam Planting Timeline — San Patricio County, TX
Yam Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 1 | Jan 1 – Jan 15 |
| Transplant Outdoors | February 19 | Feb 19 – Mar 5 |
| Direct Sow | February 12 | Feb 12 – Mar 5 |
| Harvest | August 20 | Aug 20 – Dec 17 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
180–330 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
300 days in San Patricio County
Growing Tips for Yam in San Patricio County
Direct sow Yam outdoors after February 12 in San Patricio County when soil has warmed and frost danger has passed.
With summer highs reaching 100°F in San Patricio County, provide afternoon shade for Yam and water deeply in the morning.
Your 301.0-day growing season in San Patricio County is tight for Yam (180.0-330.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant tuber pieces in mounds of loose, rich soil. Provide sturdy trellising for climbing vines. Yams require a long, warm growing season of 8-11 months. Harvest when vines die back.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Yam in Other Locations
Frequently Asked Questions
When should I plant Yam in San Patricio County, TX?
San Patricio County is in Zone 9b with an average last frost of February 12. Plan your Yam planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Patricio County, TX?
San Patricio County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 12 and first fall frost is December 9.
Your San Patricio County Garden Planner — Free
A 24-page printable planner built for San Patricio County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.