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When to Plant Broccoli in Smith 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.

Smith County, Tennessee is in USDA Zone 7a. 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 3,829 feet, Smith County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Broccoli during the growing season.

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

Smith County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (94 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: Jun 7 – Jul 19
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 24
Safe Start (90%) ✓ Fits season (98 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.

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 245 gal / 100 sq ft
Broccoli needs ~1,538 GDD — county provides 4,120 GDD Excellent fit

Broccoli Planting Timeline โ€” Smith County, TN

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 โ€“ Mar 20
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow March 27 Mar 27 โ€“ Apr 17
Fall Sowing August 19 Aug 19 โ€“ Sep 2
Harvest June 12 Jun 12 โ€“ Jul 24

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

201 days

Growing Tips for Smith County

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

Level Up Your Garden

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 Smith County, TN?

Smith County is in Zone 7a with an average last frost of April 10. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Smith County, TN?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Smith County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 Smith County, TN. Local conditions may vary. Last updated: April 2026.