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When to Plant Tomatoes in St. Clair County, AL

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.

St. Clair County, Alabama is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 1, giving you a growing season of approximately 219 days.

At an elevation of 211 feet, St. Clair County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89ยฐF, providing good warmth for Tomatoes during the growing season. Clay soil retains moisture well for Tomatoes, but amend with compost to improve drainage and prevent root rot.

St. Clair County, AL (Zone 7b) Long season
219 days
Last Spring Frost March 27
219 growing days
First Fall Frost November 1

St. Clair County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Jan 30 Transplant: Apr 3 🍅 Harvest: Jun 5 – Aug 14
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Feb 6 Transplant: Apr 10 🍅 Harvest: Jun 12 – Aug 21
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 9

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 140 gal / 100 sq ft
Tomatoes needs ~1,214 GDD — county provides 3,668 GDD Excellent fit

Tomatoes Planting Timeline โ€” St. Clair County, AL

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 โ€“ Feb 20
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow April 3 Apr 3 โ€“ Apr 24
Harvest June 12 Jun 12 โ€“ Aug 21

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“85 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

219 days

Growing Tips for St. Clair County

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.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Level Up Your Garden

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 St. Clair County, AL?

St. Clair County is in Zone 7b with an average last frost of March 27. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Clair County, AL?

St. Clair County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Clair County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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 St. Clair County, AL. Local conditions may vary. Last updated: April 2026.