Blog

When to Plant Leeks in St. Clair County, AL

Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

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 Leeks during the growing season. Clay soil retains moisture well for Leeks, 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 (54 days to spare)
Start indoors: Feb 13 Transplant: Mar 20 🍅 Harvest: Jun 19 – Sep 4
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: Jun 26 – Sep 11
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 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 St. Clair County

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

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Leeks needs ~2,010 GDD — county provides 3,668 GDD Excellent fit

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

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 โ€“ Mar 6
Transplant Outdoors March 27 Mar 27 โ€“ Apr 10
Direct Sow March 13 Mar 13 โ€“ Apr 3
Fall Sowing August 23 Aug 23 โ€“ Sep 6
Harvest June 26 Jun 26 โ€“ Sep 11

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in St. Clair County

Growing Tips for Leeks in St. Clair County

Direct sow Leeks 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 Leeks. Avoid tilling when soil is wet to prevent compaction.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Level Up Your Garden

Frequently Asked Questions

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

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