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When to Plant Cauliflower in Jefferson 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.

Jefferson County, Tennessee is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 3,886 feet, Jefferson County receives approximately 44.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93ยฐF, providing good warmth for Cauliflower during the growing season.

Jefferson County, TN (Zone 7a) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (74 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Aug 5
Recommended (50%) ✓ Fits season (71 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 29

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
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 862 gal / 100 sq ft
Cauliflower needs ~1,531 GDD — county provides 3,752 GDD Excellent fit

Cauliflower Planting Timeline โ€” Jefferson County, TN

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 15 Apr 15 โ€“ Apr 29
Direct Sow April 1 Apr 1 โ€“ Apr 22
Fall Sowing August 13 Aug 13 โ€“ Aug 27
Harvest June 10 Jun 10 โ€“ Aug 12

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
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

190 days

Growing Tips for Jefferson 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 Jefferson County, TN?

Jefferson County is in Zone 7a with an average last frost of April 15. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, TN?

Jefferson County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

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