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When to Plant Tomatoes in Runnels County, TX

Runnels County, Texas Zone 8a May

What to do in May

A quick May briefing for Runnels County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 19
Avg. first frost November 15
Soil temp (4") 57°F
Watering Low
Pest pressure Moderate
Daylight 13.6 hrs
  1. Fire up the seed-starting tray: tomatoes

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Before June arrives, get these ready
  • First harvests: tomatoes

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Runnels County, Texas is in USDA Zone 8a. The average last spring frost is March 19 and the first fall frost is November 15, giving you a growing season of approximately 241 days.

At an elevation of 4,833 feet, Runnels County receives approximately 47.6 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Tomatoes during the growing season.

Runnels County, TX (Zone 8a) Long season
241 days
Last Spring Frost March 19
241 growing days
First Fall Frost November 15

Runnels County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (98 days to spare)
Start indoors: Jan 19 Transplant: Mar 23 🍅 Harvest: May 25 – Aug 3
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Jan 29 Transplant: Apr 2 🍅 Harvest: Jun 4 – Aug 13
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jun 28 – Sep 6

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 Runnels County

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

Soil pH

Your soil pH (6.3–7.1) overlaps with Tomatoes's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Runnels County is excellent for Tomatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is low (2.0%). Add 2-3 inches of compost before planting Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

4
successive plantings in your 241-day season

Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.8″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 795 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 5.2" 3" 2.2" 💧 Light watering
Apr 5.2" 4.9" 0.3" 💧 Light watering
May 5.2" 7.4" 0" ✅ Rainfall sufficient
Jun 5.2" 8.1" 0" ✅ Rainfall sufficient
Jul 5.2" 6.3" 0" ✅ Rainfall sufficient
Aug 5.2" 5.1" 0.1" 💧 Light watering
Sep 5.2" 4.2" 1" 💧 Light watering
Oct 5.2" 3.2" 2" 💧 Light watering
Nov 5.2" 1.5" 3.7" 🚿 Regular watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Runnels County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatoes 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.

Tomatoes needs ~1,269 GDD — county provides 4,217 GDD Excellent fit

Tomatoes Planting Timeline — Runnels County, TX

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 26 Mar 26 – Apr 16
Harvest June 4 Jun 4 – Aug 13

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March 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

1.2"/week · 1-2 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

241 days in Runnels County

Growing Tips for Tomatoes in Runnels County

Direct sow Tomatoes outdoors after March 19 in Runnels County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Runnels County

Your long season supports large indeterminate heirloom types

Brandywine (80d) Cherokee Purple (80d) San Marzano (80d) Mortgage Lifter (85d)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Runnels County, TX?

Runnels County is in Zone 8a with an average last frost of March 19. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Runnels County, TX?

Runnels County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 19 and first fall frost is November 15.

🌱

Your Runnels County Garden Planner — Free

A 24-page printable planner built for Runnels 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 Runnels 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.