When to Plant Kale in Ottawa County, MI
What to do in May
We've pulled the most time-sensitive tasks for Ottawa County, Michigan this May and put them front and centre. Tackle them in order.
-
Get kale in the ground
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
Coming up in June — start thinking about
- 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.
Ottawa County, Michigan is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 9, giving you a growing season of approximately 153 days.
At an elevation of 1,027 feet, Ottawa County receives approximately 41.9 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.
Ottawa County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.8
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.
Soil Compatibility in Ottawa County
How your county's soil matches Kale's growing requirements.
Soil pH
Your soil pH (5.8–6.8) overlaps with Kale's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Ottawa County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Kale will thrive.
How to Plant Kale
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Kale
Sow every 5.7 weeks. Last sowing by Jul 31 to harvest before frost.
For a dedicated fall crop, sow by Jul 31.
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 4.1" | 0" | ❄️ Dormant |
| May | 3.5" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Oct | 3.5" | 3" | 0.5" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Ottawa 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 — Ottawa County, MI
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | July 4 | Jul 4 – Aug 29 |
| Fall Sowing | July 31 | Jul 31 – Aug 14 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| 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
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
153 days in Ottawa County
Growing Tips for Kale in Ottawa County
Direct sow Kale outdoors after May 09 in Ottawa 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 Ottawa County, MI?
Ottawa County is in Zone 6a with an average last frost of May 9. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ottawa County, MI?
Ottawa County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 9.
Your Ottawa County Garden Planner — Free
A 24-page printable planner built for Ottawa County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.