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When to Plant Eggplant in St. Clair County, AL

Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.

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 Eggplant during the growing season. Clay soil retains moisture well for Eggplant, 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 16 Transplant: Apr 3 🍅 Harvest: Jun 12 – Aug 14
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Jan 23 Transplant: Apr 10 🍅 Harvest: Jun 19 – Aug 21
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Feb 11 Transplant: Apr 29 🍅 Harvest: Jul 8 – 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.

Soil Compatibility in St. Clair County

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

Soil pH

Your soil pH (5.3โ€“6.8) overlaps with Eggplant's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The clay loam soil in St. Clair County is excellent for Eggplant โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Eggplant

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Eggplant

3
successive plantings in your 219-day season

Sow every 7.4 weeks. Last sowing by Aug 08 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 335 gal / 100 sq ft

Monthly Watering Guide for Eggplant

Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Eggplant Needs Rainfall You Supplement Action
Jan โ€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Apr 4.8" 3.8" 1" ๐Ÿ’ง Light watering
May 4.8" 3.7" 1.1" ๐Ÿ’ง Light watering
Jun 4.8" 4.8" 0" โœ… Rainfall sufficient
Jul 4.8" 4.8" 0" โœ… Rainfall sufficient
Aug 4.8" 4.4" 0.4" ๐Ÿ’ง Light watering
Sep 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Oct 4.8" 3.6" 1.2" ๐Ÿ’ง Light watering
Nov 4.8" 3.4" 1.4" ๐Ÿ’ง Light watering
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in St. Clair County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Eggplant 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.

Eggplant needs ~1,256 GDD — county provides 3,668 GDD Excellent fit

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

Eggplant Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 โ€“ Feb 6
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow April 3 Apr 3 โ€“ Apr 24
Harvest June 19 Jun 19 โ€“ Aug 21

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

65โ€“85 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in St. Clair County

Growing Tips for Eggplant in St. Clair County

Direct sow Eggplant outdoors after March 27 in St. Clair County when soil has warmed and frost danger has passed.

With St. Clair County's clay soil (26% clay), work in 3-4 inches of compost before planting Eggplant. Avoid tilling when soil is wet to prevent compaction.

Common pests for Eggplant 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 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Eggplant in St. Clair County, AL?

St. Clair County is in Zone 7b with an average last frost of March 27. Plan your Eggplant 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.

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