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When to Plant Leeks in Thomas County, GA

Thomas County, Georgia Zone 9a May

Your May game plan for Thomas County, Georgia

Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 4
Avg. first frost November 22
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
To set up a strong June, finish these tasks
  • First harvests: leeks

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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.

Thomas County, Georgia is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 22, giving you a growing season of approximately 263 days.

At an elevation of 302 feet, Thomas County receives approximately 58.3 inches of rainfall annually with predominantly clay loam soil. Summer highs average 95°F, so Leeks may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Leeks, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

Thomas County, GA (Zone 9a) Long season
263 days
Last Spring Frost March 4
263 growing days
First Fall Frost November 22
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Thomas County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Jan 24 Transplant: Feb 21 🍅 Harvest: May 23 – Aug 8
Recommended (50%) ✓ Fits season (95 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Jun 3 – Aug 19
Safe Start (90%) ✓ Fits season (98 days to spare)
Start indoors: Feb 25 Transplant: Mar 25 🍅 Harvest: Jun 24 – 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 Thomas County

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

Soil pH

Your soil pH (5.5–6.5) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

The clay loam soil in Thomas County is excellent for Leeks — 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 8 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

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 4.9" 0" ❄️ Dormant
Feb 4.8" 0" ❄️ Dormant
Mar 3.5" 6" 0" ✅ Rainfall sufficient
Apr 3.5" 4.6" 0" ✅ Rainfall sufficient
May 3.5" 4.1" 0" ✅ Rainfall sufficient
Jun 3.5" 4.6" 0" ✅ Rainfall sufficient
Jul 3.5" 6" 0" ✅ Rainfall sufficient
Aug 3.5" 5.5" 0" ✅ Rainfall sufficient
Sep 3.5" 4.7" 0" ✅ Rainfall sufficient
Oct 3.5" 3.4" 0.1" 💧 Light watering
Nov 3.5" 4.9" 0" ✅ Rainfall sufficient
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Thomas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Leeks 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" — every day above 50°F 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.

Leeks needs ~2,550 GDD — county provides 5,588 GDD Excellent fit

Leeks Planting Timeline — Thomas County, GA

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors March 4 Mar 4 – Mar 18
Direct Sow February 11 Feb 11 – Mar 4
Harvest June 3 Jun 3 – Aug 19
Fall Sowing September 27 Sep 27 – Oct 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

263 days in Thomas County

Growing Tips for Leeks in Thomas County

Direct sow Leeks outdoors after March 04 in Thomas County when soil has warmed and frost danger has passed.

With Thomas County's clay soil (31% 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Thomas County, GA?

Thomas County is in Zone 9a with an average last frost of March 4. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thomas County, GA?

Thomas County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 22.

🌱

Your Thomas County Garden Planner — Free

A 24-page printable planner built for Thomas County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Thomas County, GA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.