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When to Plant Cauliflower in Clark County, OH

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.

Clark County, Ohio is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 21, giving you a growing season of approximately 186 days.

At an elevation of 721 feet, Clark County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Cauliflower during the growing season.

Clark County, OH (Zone 6a) Moderate season
186 days
Last Spring Frost April 18
186 growing days
First Fall Frost October 21

Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 15
Safe Start (90%) ✓ Fits season (59 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jul 4 – Sep 5

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
0.8″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,927 gal / 100 sq ft
Cauliflower needs ~1,240 GDD — county provides 2,976 GDD Excellent fit

Cauliflower Planting Timeline โ€” Clark County, OH

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors April 18 Apr 18 โ€“ May 2
Direct Sow April 4 Apr 4 โ€“ Apr 25
Fall Sowing August 12 Aug 12 โ€“ Aug 26
Harvest June 13 Jun 13 โ€“ Aug 15

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 Transplant Outdoors
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 6a

Growing Season

186 days

Growing Tips for Clark 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 Clark County, OH?

Clark County is in Zone 6a with an average last frost of April 18. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clark County, OH?

Clark County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clark County gardeners in Zone 6a 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 Clark County, OH. Local conditions may vary. Last updated: April 2026.