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When to Plant Sweet Potatoes in Morris County, TX

Morris County, Texas Zone 8b May

Morris County, Texas gardeners: here's your May plan

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 12
Avg. first frost November 11
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
June will be here before you know it — start on
  • 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.

Morris County, Texas is in USDA Zone 8b. The average last spring frost is March 12 and the first fall frost is November 11, giving you a growing season of approximately 244 days.

At an elevation of 185 feet, Morris County receives approximately 69.9 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.

Morris County, TX (Zone 8b) Long season
244 days
Last Spring Frost March 12
244 growing days
First Fall Frost November 11
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Morris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Jan 16 Transplant: Mar 20 🍅 Harvest: Jun 19 – Aug 7
Recommended (50%) ✓ Fits season (90 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jun 25 – Aug 13
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jul 20 – Sep 7

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 Morris County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

Sandy soil in Morris 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 (1.9%). 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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.4" 0" ❄️ Dormant
Mar 4.3" 4" 0.3" 💧 Light watering
Apr 4.3" 7.4" 0" ✅ Rainfall sufficient
May 4.3" 11.5" 0" ✅ Rainfall sufficient
Jun 4.3" 11.4" 0" ✅ Rainfall sufficient
Jul 4.3" 8.2" 0" ✅ Rainfall sufficient
Aug 4.3" 9.1" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Morris 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 5,368 GDD Excellent fit

Sweet Potatoes Planting Timeline — Morris County, TX

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors March 26 Mar 26 – Apr 9
Direct Sow March 19 Mar 19 – Apr 9
Harvest June 25 Jun 25 – Aug 13

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8b

📆 Growing Season

244 days in Morris County

Growing Tips for Sweet Potatoes in Morris County

Direct sow Sweet Potatoes outdoors after March 12 in Morris County when soil has warmed and frost danger has passed.

Sandy soil in Morris 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 Morris 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 Morris County, TX?

Morris County is in Zone 8b with an average last frost of March 12. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Morris County, TX?

Morris County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 12 and first fall frost is November 11.

🌱

Your Morris County Garden Planner — Free

A 24-page printable planner built for Morris County (Zone 8b). 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 Morris 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.