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When to Plant Leeks in DeKalb County, TN

DeKalb County, Tennessee Zone 7b May

May in the garden — DeKalb County, Tennessee

May is a pivotal month for DeKalb County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 10
Avg. first frost October 28
Soil temp (4") 60°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start leeks under lights

    These need a head start before your last frost (April 10). Sow into cells now so you're ready to transplant in a few weeks.

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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.

DeKalb County, Tennessee is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 28, giving you a growing season of approximately 201 days.

At an elevation of 3,805 feet, DeKalb County receives approximately 52.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Leeks during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

DeKalb County, TN (Zone 7b) Long season
201 days
Last Spring Frost April 10
201 growing days
First Fall Frost October 28

DeKalb County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: Jul 5 – Sep 20
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jul 10 – Sep 25
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jul 21 – Oct 6

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 DeKalb County

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

Soil pH

Your soil pH (5.6–6.6) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in DeKalb County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 4.5" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 3.5" 4" 0" ✅ Rainfall sufficient
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.6" 0" ✅ Rainfall sufficient
Jul 3.5" 4.9" 0" ✅ Rainfall sufficient
Aug 3.5" 4.5" 0" ✅ Rainfall sufficient
Sep 3.5" 4.2" 0" ✅ Rainfall sufficient
Oct 3.5" 2.9" 0.6" 💧 Light watering
Nov 4.1" 0" ❄️ Dormant
Dec 4.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in DeKalb 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 ~2,100 GDD — county provides 3,517 GDD Excellent fit

Leeks Planting Timeline — DeKalb County, TN

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Harvest July 10 Jul 10 – Sep 25
Fall Sowing August 19 Aug 19 – Sep 2

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

Month-by-Month Timeline

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

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 7b

📆 Growing Season

201 days in DeKalb County

Growing Tips for Leeks in DeKalb County

Direct sow Leeks outdoors after April 10 in DeKalb County when soil has warmed and frost danger has passed.

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 DeKalb County, TN?

DeKalb County is in Zone 7b with an average last frost of April 10. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeKalb County, TN?

DeKalb County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 28.

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Your DeKalb County Garden Planner — Free

A 24-page printable planner built for DeKalb County (Zone 7b). 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 DeKalb County, TN. 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.