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When to Plant Potatoes in Lamar County, TX

Lamar County, Texas Zone 8a May

Your May gardening checklist

Your garden in Lamar County, Texas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 15
Avg. first frost November 15
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Time to start potatoes inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

June prep starts now
  • First harvests: potatoes

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

Lamar County, Texas is in USDA Zone 8a. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.

At an elevation of 95 feet, Lamar County receives approximately 59.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Potatoes during the growing season. Sandy soil warms quickly in spring — great for early planting — but Potatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Potatoes root diseases.

Lamar County, TX (Zone 8a) Long season
245 days
Last Spring Frost March 15
245 growing days
First Fall Frost November 15

Lamar County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Jan 17 Transplant: Mar 21 🍅 Harvest: May 30 – Aug 8
Recommended (50%) ✓ Fits season (91 days to spare)
Start indoors: Jan 25 Transplant: Mar 29 🍅 Harvest: Jun 7 – Aug 16
Safe Start (90%) ✓ Fits season (81 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jul 2 – Sep 10

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 Lamar County

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Potatoes's range (5.0–6.5), though not a perfect match.

Soil Texture

Sandy soil in Lamar County warms quickly in spring but drains fast. 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 Potatoes.

How to Plant Potatoes

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

Succession Planting Potatoes

4
successive plantings in your 245-day season

Sow every 8 weeks. Last sowing by Jul 18 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.7" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 6.8" 0" ✅ Rainfall sufficient
May 4.3" 8.8" 0" ✅ Rainfall sufficient
Jun 4.3" 9.7" 0" ✅ Rainfall sufficient
Jul 4.3" 8" 0" ✅ Rainfall sufficient
Aug 4.3" 7.1" 0" ✅ Rainfall sufficient
Sep 4.3" 5.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Lamar County). Supplement amounts are based on average rainfall — 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" — 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.

Potatoes needs ~1,734 GDD — county provides 4,471 GDD Excellent fit

Potatoes Planting Timeline — Lamar County, TX

Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors March 29 Mar 29 – Apr 12
Direct Sow March 22 Mar 22 – Apr 12
Harvest June 7 Jun 7 – Aug 16

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

245 days in Lamar County

Growing Tips for Potatoes in Lamar County

Direct sow Potatoes outdoors after March 15 in Lamar County when soil has warmed and frost danger has passed.

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

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 Lamar County, TX?

Lamar County is in Zone 8a with an average last frost of March 15. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lamar County, TX?

Lamar County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 15 and first fall frost is November 15.

🌱

Your Lamar County Garden Planner — Free

A 24-page printable planner built for Lamar County (Zone 8a). 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 Lamar 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.