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When to Plant Potatoes in Duval County, TX

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Duval County, Texas is in USDA Zone 9a. 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 102ยฐF, so Potatoes may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Potatoes root diseases.

Duval County, TX (Zone 9a) Year-round
299 days
Last Spring Frost February 13
299 growing days
First Fall Frost December 9

Duval County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (167 days to spare)
Start indoors: Dec 9 Transplant: Jan 27 🍅 Harvest: Apr 7 – Jun 16
Recommended (50%) ✓ Fits season (152 days to spare)
Start indoors: Jan 2 Transplant: Feb 20 🍅 Harvest: May 1 – Jul 10
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Jan 25 Transplant: Mar 15 🍅 Harvest: May 24 – Aug 2

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 Potatoes's growing requirements.

Soil pH

Your soil pH (6.8โ€“7.3) is more alkaline than Potatoes prefers (5.0โ€“6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Duval County is excellent for Potatoes โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Potatoes.

How to Plant Potatoes

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

Succession Planting Potatoes

5
successive plantings in your 299-day season

Sow every 8 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 607 gal / 100 sq ft

Monthly Watering Guide for Potatoes

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 Potatoes Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Mar 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Apr 4.3" 5.3" 0" โœ… Rainfall sufficient
May 4.3" 8.7" 0" โœ… Rainfall sufficient
Jun 4.3" 8.4" 0" โœ… Rainfall sufficient
Jul 4.3" 6.8" 0" โœ… Rainfall sufficient
Aug 4.3" 6" 0" โœ… Rainfall sufficient
Sep 4.3" 5.7" 0" โœ… Rainfall sufficient
Oct 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Nov 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Dec 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Duval County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

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" โ€” every day above 50ยฐF 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.

Potatoes needs ~2,518 GDD — county provides 7,950 GDD Excellent fit

Potatoes Planting Timeline โ€” Duval County, TX

Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 2 Jan 2 โ€“ Jan 16
Transplant Outdoors February 20 Feb 20 โ€“ Mar 6
Direct Sow February 13 Feb 13 โ€“ Mar 6
Harvest May 1 May 1 โ€“ Jul 10

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

70โ€“120 days

๐Ÿงช Soil pH

Needs 5โ€“6.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

299 days in Duval County

Growing Tips for Potatoes in Duval County

Direct sow Potatoes outdoors after February 13 in Duval County when soil has warmed and frost danger has passed.

With summer highs reaching 102ยฐF in Duval County, provide afternoon shade for Potatoes and water deeply in the morning.

Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Potatoes in Duval County, TX?

Duval County is in Zone 9a with an average last frost of February 13. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Duval County, TX?

Duval County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Duval County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Duval County, TX. Local conditions may vary. Last updated: April 2026.