When to Plant Kale in Mahnomen County, MN
May in the garden — Mahnomen County, Minnesota
Your Mahnomen County, Minnesota garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Time to transplant kale
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Direct-sow kale
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
June prep starts now
- Starting indoors: kale
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.
Mahnomen County, Minnesota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 27, giving you a growing season of approximately 137 days.
At an elevation of 1,223 feet, Mahnomen County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Kale to ensure they mature before fall.
Mahnomen County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
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.
Soil Compatibility in Mahnomen County
How your county's soil matches Kale's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Kale's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Mahnomen County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Kale.
Organic Matter
Organic matter is excellent (4.0%) — 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 19 to harvest before frost.
For a dedicated fall crop, sow by Jul 05.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Oct | — | 2.4" | 0" | ❄️ Dormant |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Mahnomen 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 — Mahnomen County, MN
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 1 | Apr 1 – Apr 15 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | July 8 | Jul 8 – Sep 2 |
| Fall Sowing | July 5 | Jul 5 – Jul 19 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4a
📆 Growing Season
137 days in Mahnomen County
Growing Tips for Kale in Mahnomen County
Direct sow Kale outdoors after May 13 in Mahnomen 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 Mahnomen County, MN?
Mahnomen County is in Zone 4a with an average last frost of May 13. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mahnomen County, MN?
Mahnomen County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 27.
Your Mahnomen County Garden Planner — Free
A 24-page printable planner built for Mahnomen County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.