When to Plant Kale in Sioux County, IA
Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.
Sioux County, Iowa is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 3, giving you a growing season of approximately 155 days.
At an elevation of 1,212 feet, Sioux County receives approximately 39.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Kale to ensure they mature before fall.
Sioux County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-7
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
Kale Planting Timeline — Sioux County, IA
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
| Harvest | June 26 | Jun 26 – Aug 21 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
50–70 days
Soil pH
6 – 7.5
USDA Zone
Zone 4b
Growing Season
155 days
Growing Tips for Sioux County
Direct sow or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.
Kale in Other Locations
Frequently Asked Questions
When should I plant Kale in Sioux County, IA?
Sioux County is in Zone 4b with an average last frost of May 1. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sioux County, IA?
Sioux County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 3.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Sioux County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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