When to Plant Broccoli in Shiawassee 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.
Shiawassee County, Michigan is in USDA Zone 5b. The average last spring frost is April 29 and the first fall frost is October 14, giving you a growing season of approximately 168 days.
At an elevation of 803 feet, Shiawassee County receives approximately 30.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Broccoli during the growing season.
Shiawassee County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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
Broccoli Planting Timeline — Shiawassee County, MI
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 25 | Mar 25 – Apr 8 |
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Direct Sow | April 15 | Apr 15 – May 6 |
| Fall Sowing | August 5 | Aug 5 – Aug 19 |
| Harvest | July 1 | Jul 1 – Aug 12 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
6 – 7
USDA Zone
Zone 5b
Growing Season
168 days
Growing Tips for Shiawassee 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
Level Up Your Garden
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Shiawassee County, MI?
Shiawassee County is in Zone 5b with an average last frost of April 29. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Shiawassee County, MI?
Shiawassee County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 29 and first fall frost is October 14.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Shiawassee County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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