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When to Plant Cauliflower in Williamson County, TN

Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Williamson County, Tennessee is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 24, giving you a growing season of approximately 197 days.

At an elevation of 1,865 feet, Williamson County receives approximately 41.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Cauliflower during the growing season.

Williamson County, TN (Zone 7a) Moderate season
197 days
Last Spring Frost April 10
197 growing days
First Fall Frost October 24

Williamson 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 (79 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 30 – Aug 1
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Aug 7
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,308 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Cauliflower needs ~1,240 GDD — county provides 3,152 GDD Excellent fit

Cauliflower Planting Timeline โ€” Williamson County, TN

Cauliflower 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 15 Aug 15 โ€“ Aug 29
Harvest June 5 Jun 5 โ€“ Aug 7

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 Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

55โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

197 days

Growing Tips for Williamson County

Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

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Frequently Asked Questions

When should I plant Cauliflower in Williamson County, TN?

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

What planting zone is Williamson County, TN?

Williamson County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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