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When to Plant Broccoli in Decatur County, TN

Decatur County, Tennessee Zone 7b May

Your May game plan for Decatur County, Tennessee

A quick May briefing for Decatur County, Tennessee gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 5
Avg. first frost October 27
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Get broccoli seeds going inside

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

Looking ahead to June
  • 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.

Decatur County, Tennessee is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 27, giving you a growing season of approximately 205 days.

At an elevation of 1,168 feet, Decatur County receives approximately 55 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Broccoli during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Broccoli root diseases.

Decatur County, TN (Zone 7b) Long season
205 days
Last Spring Frost April 5
205 growing days
First Fall Frost October 27
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Decatur County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (101 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 30 – Jul 11
Recommended (50%) ✓ Fits season (100 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: Jun 7 – Jul 19
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 23 – Aug 4

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 Decatur County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Broccoli prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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 205-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.2" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 6.5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Decatur 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 ~1,312 GDD — county provides 3,587 GDD Excellent fit

Broccoli Planting Timeline — Decatur County, TN

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 22 Mar 22 – Apr 12
Harvest June 7 Jun 7 – Jul 19
Fall Sowing August 18 Aug 18 – Sep 1

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 Harvest
July Harvest
August Fall Sowing
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

205 days in Decatur County

Growing Tips for Broccoli in Decatur County

Direct sow Broccoli outdoors after April 05 in Decatur 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.

Recommended Broccoli Varieties for Decatur County

Heat-tolerant broccoli — plant as early spring or fall crop

Arcadia Marathon Green Magic

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 Decatur County, TN?

Decatur County is in Zone 7b with an average last frost of April 5. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.

What planting zone is Decatur County, TN?

Decatur County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 27.

🌱

Your Decatur County Garden Planner — Free

A 24-page printable planner built for Decatur 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 Decatur 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.