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When to Plant Cauliflower in Sullivan 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.

Sullivan County, Tennessee is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 19, giving you a growing season of approximately 179 days.

At an elevation of 3,986 feet, Sullivan County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Cauliflower during the growing season.

Sullivan County, TN (Zone 6b) Moderate season
179 days
Last Spring Frost April 23
179 growing days
First Fall Frost October 19

Sullivan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7.1

Drainage

Well Drained

How Much Cauliflower to Grow

1-2 lbs
Average yield per plant
3
Plants per person
6 sq ft
Space per person

For a family of 4, plant approximately 12 cauliflower plants in about 24 sq ft. In Sullivan County's 179-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Cauliflower

Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cauliflower Needs Rainfall You Supplement Action
Jan โ€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 3.3" 0" โ„๏ธ Dormant
Mar โ€” 4.7" 0" โ„๏ธ Dormant
Apr 4.3" 3.3" 1" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jul 4.3" 4.8" 0" โœ… Rainfall sufficient
Aug 4.3" 4.9" 0" โœ… Rainfall sufficient
Sep 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Oct 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Nov โ€” 3.8" 0" โ„๏ธ Dormant
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Sullivan County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cauliflower Planting Timeline โ€” Sullivan County, TN

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest June 18 Jun 18 โ€“ Aug 20
Fall Sowing August 10 Aug 10 โ€“ Aug 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

High โ€” keep soil consistently moist

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

179 days in Sullivan County

Growing Tips for Sullivan 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in Sullivan County, TN?

Sullivan County is in Zone 6b with an average last frost of April 23. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sullivan County, TN?

Sullivan County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sullivan County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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