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When to Plant Broccoli in Warren County, OH

Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.

Warren County, Ohio is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 653 feet, Warren County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Broccoli during the growing season.

Warren County, OH (Zone 6a) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 24
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 30
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 9 – 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.

Soil Compatibility in Warren County

How your county's soil matches Broccoli's growing requirements.

Soil pH

Your soil pH (6.2โ€“6.8) is within Broccoli's preferred range (6.0โ€“7.0).

Soil Texture

The silt loam soil in Warren County is excellent for Broccoli โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) โ€” Broccoli will thrive.

How to Plant Broccoli

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Broccoli

3
successive plantings in your 189-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 274 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Broccoli

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

Month Broccoli Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
May 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jun 4.3" 4.6" 0" โœ… Rainfall sufficient
Jul 4.3" 4.7" 0" โœ… Rainfall sufficient
Aug 4.3" 4.5" 0" โœ… Rainfall sufficient
Sep 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Oct 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 2.3" 0" โ„๏ธ Dormant

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

Broccoli Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Broccoli needs ~1,369 GDD — county provides 3,449 GDD Excellent fit

Broccoli Planting Timeline โ€” Warren County, OH

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 2 Apr 2 โ€“ Apr 23
Harvest June 18 Jun 18 โ€“ Jul 30
Fall Sowing August 13 Aug 13 โ€“ Aug 27

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

189 days in Warren County

Growing Tips for Broccoli in Warren County

Direct sow Broccoli outdoors after April 16 in Warren County when soil has warmed and frost danger has passed.

Summer highs in Warren County reach 91ยฐF โ€” grow Broccoli as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Broccoli in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.

Recommended Broccoli Varieties for Warren County

Heat-tolerant broccoli โ€” plant as early spring or fall crop

Arcadia Marathon Green Magic

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Broccoli Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow plants to flower 2nd year; collect dry pods.
Storage Store airtight; viable 5 years at 35ยฐF, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial โ€” must overwinter roots.

Frequently Asked Questions

When should I plant Broccoli in Warren County, OH?

Warren County is in Zone 6a with an average last frost of April 16. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Warren County, OH?

Warren County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

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