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When to Plant Kohlrabi in Bowman County, ND

Bowman County, North Dakota Zone 4b May

Top priorities for Bowman County, North Dakota gardeners in May

A quick May briefing for Bowman County, North Dakota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 15
Avg. first frost September 24
Soil temp (4") 54°F
Watering Moderate
Pest pressure Low
Daylight 14.8 hrs
  1. Plant out kohlrabi

    Frost risk is low now in Bowman County, North Dakota. If you've been covering beds overnight, you can stop.

  2. Plant kohlrabi from seed, right in the garden

    Your soil is 54°F — warm enough for these to germinate without babying.

Coming up in June — start thinking about
  • Starting indoors: kohlrabi

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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.

Bowman County, North Dakota is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 24, giving you a growing season of approximately 132 days.

At an elevation of 753 feet, Bowman County receives approximately 25.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Kohlrabi to ensure they mature before fall.

Bowman County, ND (Zone 4b) Short season
132 days
Last Spring Frost May 15
132 growing days
First Fall Frost September 24

Bowman County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jun 30 – Aug 4
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 3 – Aug 7
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 21 – Aug 25

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 Bowman County

How your county's soil matches Kohlrabi's growing requirements.

Soil pH

Your soil pH (6.7–7.8) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Bowman County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is excellent (4.2%) — Kohlrabi will thrive.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

3
successive plantings in your 132-day season

Sow every 5.1 weeks. Last sowing by Jul 21 to harvest before frost.

For a dedicated fall crop, sow by Jul 02.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 126 gal / 100 sq ft
Drought risk

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 2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 3" 3.2" 0" ✅ Rainfall sufficient
Jun 3" 1.9" 1.1" 💧 Light watering
Jul 3" 2.3" 0.7" 💧 Light watering
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 2.1" 0.9" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bowman 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 needs ~591 GDD — county provides 1,419 GDD Excellent fit

Kohlrabi Planting Timeline — Bowman County, ND

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 3 Jul 3 – Aug 7
Fall Sowing July 2 Jul 2 – Jul 16

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
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 4b

📆 Growing Season

132 days in Bowman County

Growing Tips for Kohlrabi in Bowman County

Direct sow Kohlrabi outdoors after May 15 in Bowman 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

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kohlrabi in Bowman County, ND?

Bowman County is in Zone 4b with an average last frost of May 15. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bowman County, ND?

Bowman County, North Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 24.

🌱

Your Bowman County Garden Planner — Free

A 24-page printable planner built for Bowman 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bowman County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.