When to Plant Kohlrabi in Powell County, MT
Powell County, Montana gardeners: here's your May plan
A quick May briefing for Powell County, Montana gardeners — what's urgent, what's next, and what can wait.
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Outdoor sowing time: kohlrabi
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
Coming up in June — start thinking about
- Transplants going out: kohlrabi
- Fall sowing: kohlrabi
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.
Powell County, Montana is in USDA Zone 4b. The average last spring frost is June 6 and the first fall frost is September 8, giving you a growing season of approximately 94 days.
At an elevation of 5,514 feet, Powell County receives approximately 22.9 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Kohlrabi to ensure they mature before fall.
Powell County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.2
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 Powell County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (6.5–8.2) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Powell 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 12 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Jul 05 to harvest before frost.
For a dedicated fall crop, sow by Jun 16.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | — | 3" | 0" | ❄️ Dormant |
| Jun | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| Jul | 3" | 2.1" | 0.9" | 💧 Light watering |
| Aug | 3" | 2.2" | 0.8" | 💧 Light watering |
| Sep | 3" | 1.8" | 1.2" | 💧 Light watering |
| Oct | — | 2.1" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Powell 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 — Powell County, MT
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 25 | Apr 25 – May 9 |
| Transplant Outdoors | June 6 | Jun 6 – Jun 20 |
| Direct Sow | May 30 | May 30 – Jun 20 |
| Harvest | July 25 | Jul 25 – Aug 29 |
| Fall Sowing | June 16 | Jun 16 – Jun 30 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
94 days in Powell County
Growing Tips for Kohlrabi in Powell County
Direct sow Kohlrabi outdoors after June 06 in Powell 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 Powell County, MT?
Powell County is in Zone 4b with an average last frost of June 6. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Powell County, MT?
Powell County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is June 6 and first fall frost is September 8.
Your Powell County Garden Planner — Free
A 24-page printable planner built for Powell County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.