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When to Plant Broccoli in Madison County, TN

Madison County, Tennessee Zone 7b May

May in the garden — Madison County, Tennessee

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

Avg. last frost April 2
Avg. first frost October 28
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: broccoli

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Before June arrives, get these ready
  • First harvests: broccoli

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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.

Madison County, Tennessee is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is October 28, giving you a growing season of approximately 209 days.

At an elevation of 1,852 feet, Madison County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Broccoli during the growing season.

Madison County, TN (Zone 7b) Long season
209 days
Last Spring Frost April 2
209 growing days
First Fall Frost October 28

Madison 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 (106 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: May 28 – Jul 9
Recommended (50%) ✓ Fits season (104 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: Jun 4 – Jul 16
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 1

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 Madison County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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 209-day season

Sow every 6.9 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 111 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 3.6" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Madison County). Supplement amounts are based on average rainfall — 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" — 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.

Broccoli needs ~1,256 GDD — county provides 3,500 GDD Excellent fit

Broccoli Planting Timeline — Madison County, TN

Broccoli Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 19 Mar 19 – Apr 9
Harvest June 4 Jun 4 – Jul 16
Fall Sowing August 19 Aug 19 – Sep 2

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Madison County

Growing Tips for Broccoli in Madison County

Direct sow Broccoli outdoors after April 02 in Madison 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 →

🌾 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 35°F, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.

Frequently Asked Questions

When should I plant Broccoli in Madison County, TN?

Madison County is in Zone 7b with an average last frost of April 2. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.

What planting zone is Madison County, TN?

Madison County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is October 28.

🌱

Your Madison County Garden Planner — Free

A 24-page printable planner built for Madison 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 Madison 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.