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When to Plant Broccoli in Genesee County, MI

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.

Genesee County, Michigan is in USDA Zone 5b. The average last spring frost is April 28 and the first fall frost is October 17, giving you a growing season of approximately 172 days.

At an elevation of 1,023 feet, Genesee County receives approximately 39.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Broccoli to ensure they mature before fall.

Genesee County, MI (Zone 5b) Moderate season
172 days
Last Spring Frost April 28
172 growing days
First Fall Frost October 17

Genesee County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 28 – Aug 9
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 11
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jul 15 – Aug 26

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
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 51 gal / 100 sq ft
Broccoli needs ~975 GDD — county provides 2,236 GDD Excellent fit

Broccoli Planting Timeline โ€” Genesee County, MI

Broccoli 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 8 Aug 8 โ€“ Aug 22
Harvest June 30 Jun 30 โ€“ Aug 11

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

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

172 days

Growing Tips for Genesee 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

Level Up Your Garden

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 Genesee County, MI?

Genesee County is in Zone 5b with an average last frost of April 28. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Genesee County, MI?

Genesee County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 28 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

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