Blog

When to Plant Garlic in Shelby County, TN

Shelby County, Tennessee Zone 7b April

April to-do list for Shelby County, Tennessee

Your Shelby County, Tennessee garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost March 21
Avg. first frost November 5
Soil temp (4") 47°F
Watering Moderate
Pest pressure Moderate
Daylight 12.9 hrs

Instant PDF download. No spam, unsubscribe any time.

Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Shelby County, Tennessee is in USDA Zone 7b. The average last spring frost is March 21 and the first fall frost is November 5, giving you a growing season of approximately 229 days.

At an elevation of 3,465 feet, Shelby County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Garlic during the growing season.

Shelby County, TN (Zone 7b) Long season
229 days
Last Spring Frost March 21
229 growing days
First Fall Frost November 5

Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Transplant: Mar 14 🍅 Harvest: Jun 13 – Oct 24
Recommended (50%) ✓ Fits season (5 days to spare)
Transplant: Mar 21 🍅 Harvest: Jun 20 – Oct 31
Safe Start (90%) ✓ Fits season (5 days to spare)
Transplant: Apr 10 🍅 Harvest: Jul 10 – Nov 20

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 Shelby County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Garlic's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Garlic.

How to Plant Garlic

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Garlic

Garlic needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Garlic Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 2.2" 4.2" 0" ✅ Rainfall sufficient
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 5.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.2" 3.5" 0" ✅ Rainfall sufficient
Dec 3.7" 0" ❄️ Dormant

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

Garlic 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.

Garlic needs ~2,764 GDD — county provides 3,835 GDD Excellent fit

Garlic Planting Timeline — Shelby County, TN

Garlic Planting Calendar

Activity When Date Range
Fall Sowing September 24 Sep 24 – Oct 8

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September Fall Sowing
October Fall Sowing
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

229 days in Shelby County

Growing Tips for Garlic in Shelby County

Direct sow Garlic outdoors after March 21 in Shelby County when soil has warmed and frost danger has passed.

Your 229.0-day growing season in Shelby County is tight for Garlic (90.0-240.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Shelby County, TN?

Shelby County is in Zone 7b with an average last frost of March 21. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, TN?

Shelby County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 21 and first fall frost is November 5.

🌱

Your Shelby County Garden Planner — Free

A 24-page printable planner built for Shelby 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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