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When to Plant Broccoli in Shelby County, TN

Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.

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 89ยฐF, providing good warmth for Broccoli 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 (127 days to spare)
Start indoors: Feb 7 Transplant: Mar 14 🍅 Harvest: May 16 – Jun 27
Recommended (50%) ✓ Fits season (124 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 23 – Jul 4
Safe Start (90%) ✓ Fits season (124 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 24

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 Broccoli's growing requirements.

Soil pH

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

Soil Texture

The silt loam soil in Shelby County is excellent for Broccoli โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Broccoli

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

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

Succession Planting Broccoli

4
successive plantings in your 229-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 330 gal / 100 sq ft

Monthly Watering Guide for Broccoli

Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Broccoli Needs Rainfall You Supplement Action
Jan โ€” 3.3" 0" โ„๏ธ Dormant
Feb โ€” 3.8" 0" โ„๏ธ Dormant
Mar 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Apr 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 4.6" 0" โœ… Rainfall sufficient
Jul 4.3" 5.1" 0" โœ… Rainfall sufficient
Aug 4.3" 4.7" 0" โœ… Rainfall sufficient
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Nov 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Dec โ€” 3.7" 0" โ„๏ธ Dormant

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

Broccoli 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.

Broccoli needs ~1,256 GDD — county provides 3,835 GDD Excellent fit

Broccoli Planting Timeline โ€” Shelby County, TN

Broccoli Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 โ€“ Feb 28
Transplant Outdoors March 21 Mar 21 โ€“ Apr 4
Direct Sow March 7 Mar 7 โ€“ Mar 28
Harvest May 23 May 23 โ€“ Jul 4
Fall Sowing August 27 Aug 27 โ€“ Sep 10

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

229 days in Shelby County

Growing Tips for Broccoli in Shelby County

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

Common pests for Broccoli in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Broccoli Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow plants to flower 2nd year; collect dry pods.
Storage Store airtight; viable 5 years at 35ยฐF, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial โ€” must overwinter roots.

Frequently Asked Questions

When should I plant Broccoli in Shelby County, TN?

Shelby County is in Zone 7b with an average last frost of March 21. Plan your Broccoli planting based on this frost date โ€” 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.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Shelby 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 Shelby County, TN. Local conditions may vary. Last updated: April 2026.