When to Plant Kale in Mitchell 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.
Mitchell County, Iowa is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.
At an elevation of 506 feet, Mitchell County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Kale to ensure they mature before fall.
Mitchell County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.3
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.
Soil Compatibility in Mitchell County
How your county's soil matches Kale's growing requirements.
Soil pH
Your soil pH (5.9–7.3) overlaps with Kale's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Mitchell County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Kale will thrive.
How to Plant Kale
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Kale
Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.
For a dedicated fall crop, sow by Jul 15.
Plant Water Budget
Monthly Watering Guide for Kale
Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Kale Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Oct | 3.5" | 2.4" | 1.1" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Mitchell County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kale Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Kale Planting Timeline — Mitchell County, IA
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | June 28 | Jun 28 – Aug 23 |
| Fall Sowing | July 15 | Jul 15 – Jul 29 |
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
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
157 days in Mitchell County
Growing Tips for Kale in Mitchell County
Direct sow Kale outdoors after May 03 in Mitchell County when soil has warmed and frost danger has passed.
Common pests for Kale in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
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 Mitchell County, IA?
Mitchell County is in Zone 4b with an average last frost of May 3. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mitchell County, IA?
Mitchell County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 7.
Plan Your Garden with Confidence
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