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When to Plant Broccoli in Knox 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.

Knox County, Ohio is in USDA Zone 5b. The average last spring frost is April 29 and the first fall frost is October 15, giving you a growing season of approximately 169 days.

At an elevation of 861 feet, Knox County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Broccoli during the growing season.

Knox County, OH (Zone 5b) Moderate season
169 days
Last Spring Frost April 29
169 growing days
First Fall Frost October 15

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

How Much Broccoli 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 broccoli plants in about 24 sq ft. In Knox County's 169-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

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€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr 4.3" 3" 1.3" ๐Ÿ’ง Light watering
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jul 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Aug 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Sep 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Oct 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Nov โ€” 2.1" 0" โ„๏ธ Dormant
Dec โ€” 1.7" 0" โ„๏ธ Dormant

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

Broccoli Planting Timeline โ€” Knox County, OH

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 โ€“ Apr 8
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 15 Apr 15 โ€“ May 6
Harvest July 1 Jul 1 โ€“ Aug 12
Fall Sowing August 6 Aug 6 โ€“ Aug 20

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 โ€”
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

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

169 days in Knox County

Growing Tips for Knox County

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 Knox County, OH?

Knox County is in Zone 5b with an average last frost of April 29. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Knox County, OH?

Knox County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 29 and first fall frost is October 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 5b 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 Knox County, OH. Local conditions may vary. Last updated: April 2026.