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When to Plant Broccoli in Franklin 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.

Franklin County, Ohio is in USDA Zone 6a. The average last spring frost is April 20 and the first fall frost is October 21, giving you a growing season of approximately 184 days.

At an elevation of 1,278 feet, Franklin County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Broccoli during the growing season.

Franklin County, OH (Zone 6a) Moderate season
184 days
Last Spring Frost April 20
184 growing days
First Fall Frost October 21

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 15 – Jul 27
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 3
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jul 6 – Aug 17

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 Franklin County

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

Soil pH

Your soil pH (6.2โ€“6.9) is within Broccoli's preferred range (6.0โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) 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 184-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 126 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€” 1.9" 0" โ„๏ธ Dormant
Feb โ€” 2" 0" โ„๏ธ Dormant
Mar โ€” 3.1" 0" โ„๏ธ Dormant
Apr 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
May 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jun 4.3" 4.4" 0" โœ… Rainfall sufficient
Jul 4.3" 4.5" 0" โœ… Rainfall sufficient
Aug 4.3" 4.7" 0" โœ… Rainfall sufficient
Sep 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Franklin 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 ~1,256 GDD — county provides 3,082 GDD Excellent fit

Broccoli Planting Timeline โ€” Franklin County, OH

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 โ€“ Mar 30
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow April 6 Apr 6 โ€“ Apr 27
Harvest June 22 Jun 22 โ€“ Aug 3
Fall Sowing August 12 Aug 12 โ€“ Aug 26

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

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

184 days in Franklin County

Growing Tips for Broccoli in Franklin County

Direct sow Broccoli outdoors after April 20 in Franklin County when soil has warmed and frost danger has passed.

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.

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 Franklin County, OH?

Franklin County is in Zone 6a with an average last frost of April 20. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Franklin County, OH?

Franklin County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 20 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

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