When to Plant Broccoli in Delta 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.
Delta County, Michigan is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is October 14, giving you a growing season of approximately 155 days.
At an elevation of 921 feet, Delta County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Broccoli to ensure they mature before fall.
Delta County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.8
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Broccoli Planting Timeline — Delta County, MI
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 31 | Mar 31 – Apr 14 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | May 5 | May 5 – May 26 |
| Fall Sowing | July 22 | Jul 22 – Aug 5 |
| Harvest | July 14 | Jul 14 – Aug 25 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing 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 4b
Growing Season
155 days
Growing Tips for Delta 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 Delta County, MI?
Delta County is in Zone 4b with an average last frost of May 12. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Delta County, MI?
Delta County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is October 14.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Delta County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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