Blog

When to Plant Sweet Potatoes in Dallam County, TX

Dallam County, Texas Zone 6b May

May to-do list for Dallam County, Texas

Your Dallam County, Texas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 26
Avg. first frost October 14
Soil temp (4") 54°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Transplant sweet potatoes outside

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Direct-sow sweet potatoes

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

June will be here before you know it — start on
  • Starting indoors: sweet potatoes

Instant PDF download. No spam, unsubscribe any time.

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.

Dallam County, Texas is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 14, giving you a growing season of approximately 171 days.

At an elevation of 3,388 feet, Dallam County receives approximately 54.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Potatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Dallam County, TX (Zone 6b) Moderate season
171 days
Last Spring Frost April 26
171 growing days
First Fall Frost October 14

Dallam County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Feb 23 Transplant: May 4 🍅 Harvest: Aug 3 – Sep 21
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 1 Transplant: May 10 🍅 Harvest: Aug 9 – Sep 27
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Mar 13 Transplant: May 22 🍅 Harvest: Aug 21 – Oct 9

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 Dallam County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (7.9–8.4) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Dallam County warms quickly in spring but drains fast. Sweet Potatoes will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting Sweet Potatoes.

How to Plant Sweet Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 4" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 9.9" 0" ✅ Rainfall sufficient
Aug 4.3" 11.7" 0" ✅ Rainfall sufficient
Sep 4.3" 8" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dallam 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 needs ~2,310 GDD — county provides 3,762 GDD Excellent fit

Sweet Potatoes Planting Timeline — Dallam County, TX

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest August 9 Aug 9 – Sep 27

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

171 days in Dallam County

Growing Tips for Sweet Potatoes in Dallam County

Direct sow Sweet Potatoes outdoors after April 26 in Dallam County when soil has warmed and frost danger has passed.

Sandy soil in Dallam County dries quickly — mulch Sweet Potatoes with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Dallam 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

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Dallam County, TX?

Dallam County is in Zone 6b with an average last frost of April 26. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dallam County, TX?

Dallam County, Texas is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 14.

🌱

Your Dallam County Garden Planner — Free

A 24-page printable planner built for Dallam County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Dallam 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.