When to Plant Sweet Potatoes in Duval County, TX
What to do in May
Your Duval County, Texas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Basket week: sweet potatoes
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
To set up a strong June, finish these tasks
- First harvests: sweet potatoes
Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.
Duval County, Texas is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 9, giving you a growing season of approximately 299 days.
At an elevation of 4,259 feet, Duval County receives approximately 55.2 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.
Duval County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.3
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 Duval County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Duval County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
Monthly Watering Guide for Sweet Potatoes
Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sweet Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Mar | 4.3" | 4" | 0.3" | 💧 Light watering |
| Apr | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Dec | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Duval County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Potatoes 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.
Sweet Potatoes Planting Timeline — Duval County, TX
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 2 | Jan 2 – Jan 16 |
| Transplant Outdoors | February 20 | Feb 20 – Mar 6 |
| Direct Sow | February 13 | Feb 13 – Mar 6 |
| Harvest | May 22 | May 22 – Jul 10 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
299 days in Duval County
Growing Tips for Sweet Potatoes in Duval County
Direct sow Sweet Potatoes outdoors after February 13 in Duval County when soil has warmed and frost danger has passed.
With summer highs reaching 102°F in Duval County, provide afternoon shade for Sweet Potatoes and water deeply in the morning.
General growing tips
Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Duval County, TX?
Duval County is in Zone 9b with an average last frost of February 13. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Duval County, TX?
Duval County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 9.
Your Duval County Garden Planner — Free
A 24-page printable planner built for Duval 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.