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When to Plant Tomatoes in Grant County, AR

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.

Grant County, Arkansas is in USDA Zone 7b. The average last spring frost is March 20 and the first fall frost is November 11, giving you a growing season of approximately 236 days.

At an elevation of 498 feet, Grant County receives approximately 51.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Tomatoes during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tomatoes root diseases.

Grant County, AR (Zone 7b) Long season
236 days
Last Spring Frost March 20
236 growing days
First Fall Frost November 11

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: May 29 – Aug 7
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Jan 30 Transplant: Apr 3 🍅 Harvest: Jun 5 – Aug 14
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3

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 Grant County

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

Soil pH

Your soil pH (5.3โ€“6.6) is more acidic than Tomatoes prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

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

Succession Planting Tomatoes

4
successive plantings in your 236-day season

Sow every 6.9 weeks. Last sowing by Aug 18 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.9″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 607 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€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 4.6" 0" โ„๏ธ Dormant
Mar 5.2" 4.4" 0.8" ๐Ÿ’ง Light watering
Apr 5.2" 3.8" 1.4" ๐Ÿ’ง Light watering
May 5.2" 3.6" 1.6" ๐Ÿ’ง Light watering
Jun 5.2" 4.2" 1" ๐Ÿ’ง Light watering
Jul 5.2" 5" 0.2" ๐Ÿ’ง Light watering
Aug 5.2" 5.5" 0" โœ… Rainfall sufficient
Sep 5.2" 3.6" 1.6" ๐Ÿ’ง Light watering
Oct 5.2" 3.7" 1.5" ๐Ÿ’ง Light watering
Nov 5.2" 4.4" 0.8" ๐Ÿ’ง Light watering
Dec โ€” 4.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Grant 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 ~1,486 GDD — county provides 4,838 GDD Excellent fit

Tomatoes Planting Timeline โ€” Grant County, AR

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 โ€“ Feb 13
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Direct Sow March 27 Mar 27 โ€“ Apr 17
Harvest June 5 Jun 5 โ€“ Aug 14

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
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 Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

236 days in Grant County

Growing Tips for Tomatoes in Grant County

Direct sow Tomatoes outdoors after March 20 in Grant 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 Grant County

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 Grant County, AR?

Grant County is in Zone 7b with an average last frost of March 20. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, AR?

Grant County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 20 and first fall frost is November 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grant County gardeners in Zone 7b 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 Grant County, AR. Local conditions may vary. Last updated: April 2026.