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When to Plant Sweet Potatoes in Waller County, TX

Waller County, Texas Zone 9a May

This month in Waller County, Texas

Each item below is timed to Waller County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 19
Avg. first frost December 4
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the sweet potatoes

    If you can't use it all right away, check the food-preservation section of your planner.

Looking ahead to June
  • First harvests: sweet potatoes

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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.

Waller County, Texas is in USDA Zone 9a. The average last spring frost is February 19 and the first fall frost is December 4, giving you a growing season of approximately 288 days.

At an elevation of 376 feet, Waller County receives approximately 64.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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.

Waller County, TX (Zone 9a) Year-round
288 days
Last Spring Frost February 19
288 growing days
First Fall Frost December 4

Waller County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Dec 31 Transplant: Feb 18 🍅 Harvest: May 20 – Jul 8
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Jan 8 Transplant: Feb 26 🍅 Harvest: May 28 – Jul 16
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Jan 26 Transplant: Mar 16 🍅 Harvest: Jun 15 – Aug 3

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 Waller County

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

Soil pH

Your soil pH (5.6–6.2) is within Sweet Potatoes's preferred range (5.5–6.5).

Soil Texture

Sandy soil in Waller 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 moderate (2.0%). Annual compost additions will help 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 176 gal / 100 sq ft

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 1.7" 0" ❄️ Dormant
Feb 4.3" 2.4" 1.9" 💧 Light watering
Mar 4.3" 4.6" 0" ✅ Rainfall sufficient
Apr 4.3" 7.3" 0" ✅ Rainfall sufficient
May 4.3" 8.9" 0" ✅ Rainfall sufficient
Jun 4.3" 9.1" 0" ✅ Rainfall sufficient
Jul 4.3" 7.9" 0" ✅ Rainfall sufficient
Aug 4.3" 7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 4.3" 1.7" 2.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Waller 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 ~2,231 GDD — county provides 6,141 GDD Excellent fit

Sweet Potatoes Planting Timeline — Waller County, TX

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 8 Jan 8 – Jan 22
Transplant Outdoors February 26 Feb 26 – Mar 12
Direct Sow February 19 Feb 19 – Mar 12
Harvest May 28 May 28 – Jul 16

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

Month-by-Month Timeline

MonthActivities
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: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

288 days in Waller County

Growing Tips for Sweet Potatoes in Waller County

Direct sow Sweet Potatoes outdoors after February 19 in Waller County when soil has warmed and frost danger has passed.

Sandy soil in Waller 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.

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 Waller County, TX?

Waller County is in Zone 9a with an average last frost of February 19. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Waller County, TX?

Waller County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 19 and first fall frost is December 4.

🌱

Your Waller County Garden Planner — Free

A 24-page printable planner built for Waller 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.

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