When to Plant Cauliflower in Winnebago County, IL
Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.
Winnebago County, Illinois is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.
At an elevation of 1,318 feet, Winnebago County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Cauliflower during the growing season.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-7.3
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
Cauliflower Planting Timeline — Winnebago County, IL
Cauliflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Fall Sowing | August 3 | Aug 3 – Aug 17 |
| Harvest | June 21 | Jun 21 – Aug 23 |
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 | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
High — keep soil consistently moist
Days to Maturity
55–100 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
169 days
Growing Tips for Winnebago County
Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Cauliflower in Other Locations
Frequently Asked Questions
When should I plant Cauliflower in Winnebago County, IL?
Winnebago County is in Zone 5a with an average last frost of April 26. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Winnebago County, IL?
Winnebago County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 12.
Plan Your Garden with Confidence
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