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When to Plant Cauliflower in Washington 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.

Washington County, Ohio is in USDA Zone 6a. The average last spring frost is April 28 and the first fall frost is October 19, giving you a growing season of approximately 174 days.

At an elevation of 803 feet, Washington County receives approximately 30.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Cauliflower during the growing season.

Washington County, OH (Zone 6a) Moderate season
174 days
Last Spring Frost April 28
174 growing days
First Fall Frost October 19

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – Aug 18
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jul 13 – Sep 14

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
0.9″/week
Watering frequency 2-3 times/week
Season total 1,401 gal / 100 sq ft
Drought risk

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

Cauliflower needs ~1,298 GDD — county provides 2,914 GDD Excellent fit

Cauliflower Planting Timeline โ€” Washington County, OH

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 โ€“ Apr 7
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 14 Apr 14 โ€“ May 5
Fall Sowing August 10 Aug 10 โ€“ Aug 24
Harvest June 23 Jun 23 โ€“ Aug 25

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 Direct Sow
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

174 days

Growing Tips for Washington 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 Washington County, OH?

Washington County is in Zone 6a with an average last frost of April 28. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, OH?

Washington County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 28 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

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