When to Plant Kohlrabi in Lake County, MT
May to-do list for Lake County, Montana
Your Lake County, Montana 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 kohlrabi
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Scatter kohlrabi into prepared beds
Your soil is 36°F — warm enough for these to germinate without babying.
Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.
Lake County, Montana is in USDA Zone 6a. The average last spring frost is May 31 and the first fall frost is September 12, giving you a growing season of approximately 104 days.
At an elevation of 6,938 feet, Lake County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Kohlrabi during the growing season. With low rainfall, drip irrigation is essential for growing Kohlrabi successfully. Mulch heavily to conserve soil moisture.
Lake County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
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 Lake County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (6.6–7.7) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Lake County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Kohlrabi.
How to Plant Kohlrabi
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Jul 09 to harvest before frost.
For a dedicated fall crop, sow by Jul 04.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Kohlrabi
Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Kohlrabi Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| Jun | 3" | 0.9" | 2.1" | 🚿 Regular watering |
| Jul | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Aug | 3" | 1.2" | 1.8" | 🚿 Regular watering |
| Sep | 3" | 1.1" | 1.9" | 🚿 Regular watering |
| Oct | — | 1.1" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lake County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kohlrabi 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.
Kohlrabi Planting Timeline — Lake County, MT
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 26 | Apr 26 – May 10 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | July 19 | Jul 19 – Aug 23 |
| Fall Sowing | July 4 | Jul 4 – Jul 18 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
104 days in Lake County
Growing Tips for Kohlrabi in Lake County
Direct sow Kohlrabi outdoors after May 31 in Lake County when soil has warmed and frost danger has passed.
Common pests for Kohlrabi 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 in spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Kohlrabi in Other Locations
Frequently Asked Questions
When should I plant Kohlrabi in Lake County, MT?
Lake County is in Zone 6a with an average last frost of May 31. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, MT?
Lake County, Montana is in USDA Hardiness Zone 6a. The average last spring frost is May 31 and first fall frost is September 12.
Your Lake County Garden Planner — Free
A 24-page printable planner built for Lake 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.