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When to Plant Tomatoes in Harrison County, TX

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.

Harrison County, Texas is in USDA Zone 8a. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.

At an elevation of 168 feet, Harrison County receives approximately 63.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Tomatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Tomatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tomatoes root diseases.

Harrison County, TX (Zone 8a) Long season
246 days
Last Spring Frost March 13
246 growing days
First Fall Frost November 14

Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: May 21 – Jul 30
Recommended (50%) ✓ Fits season (99 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: May 29 – Aug 7
Safe Start (90%) ✓ Fits season (92 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 30

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 Harrison County

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

Soil pH

Your soil pH (5.3โ€“6.8) overlaps with Tomatoes's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

Sandy soil in Harrison County warms quickly in spring but drains fast. Tomatoes will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Tomatoes.

Organic Matter

Organic matter is low (1.8%). 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 246-day season

Sow every 6.9 weeks. Last sowing by Aug 21 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.1″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,031 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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar 5.2" 4.4" 0.8" ๐Ÿ’ง Light watering
Apr 5.2" 6" 0" โœ… Rainfall sufficient
May 5.2" 9.7" 0" โœ… Rainfall sufficient
Jun 5.2" 11" 0" โœ… Rainfall sufficient
Jul 5.2" 7.9" 0" โœ… Rainfall sufficient
Aug 5.2" 7.3" 0" โœ… Rainfall sufficient
Sep 5.2" 6.3" 0" โœ… Rainfall sufficient
Oct 5.2" 4" 1.2" ๐Ÿ’ง Light watering
Nov 5.2" 2.3" 2.9" ๐Ÿšฟ Regular watering
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Harrison County). Supplement amounts are based on average rainfall โ€” 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" 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.

Tomatoes needs ~1,595 GDD — county provides 5,412 GDD Excellent fit

Tomatoes Planting Timeline โ€” Harrison County, TX

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 โ€“ Feb 6
Transplant Outdoors March 27 Mar 27 โ€“ Apr 10
Direct Sow March 20 Mar 20 โ€“ Apr 10
Harvest May 29 May 29 โ€“ Aug 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

246 days in Harrison County

Growing Tips for Tomatoes in Harrison County

Direct sow Tomatoes outdoors after March 13 in Harrison County when soil has warmed and frost danger has passed.

Sandy soil in Harrison County dries quickly โ€” mulch Tomatoes with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96ยฐF in Harrison County, provide afternoon shade for Tomatoes and water deeply in the morning.

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 Harrison County

Heat-set varieties that pollinate reliably above 90ยฐF

Solar Fire Florida 91 Phoenix Heat Wave II

Your long season supports large indeterminate heirloom types

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

Disease-resistant varieties for your humid climate

Mountain Merit (VF) Defiant (LB) Iron Lady (EB/LB/SF)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ 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 35ยฐF, 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 Harrison County, TX?

Harrison County is in Zone 8a with an average last frost of March 13. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harrison County, TX?

Harrison County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 13 and first fall frost is November 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harrison County gardeners in Zone 8a 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 Harrison County, TX. Local conditions may vary. Last updated: April 2026.