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When to Plant Kohlrabi in Ramsey County, MN

Ramsey County, Minnesota Zone 5a May

What to do in May

We've pulled the most time-sensitive tasks for Ramsey County, Minnesota this May and put them front and centre. Tackle them in order.

Avg. last frost April 23
Avg. first frost October 9
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Fire up the seed-starting tray: kohlrabi

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Coming up in June — start thinking about
  • First harvests: 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.

Ramsey County, Minnesota is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 9, giving you a growing season of approximately 169 days.

At an elevation of 1,059 feet, Ramsey County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Kohlrabi to ensure they mature before fall.

Ramsey County, MN (Zone 5a) Moderate season
169 days
Last Spring Frost April 23
169 growing days
First Fall Frost October 9

Ramsey County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 5 – Jul 10
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 11 – Jul 16
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jul 1 – Aug 5

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 Ramsey County

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

Soil pH

Your soil pH (6.2–7.0) is within Kohlrabi's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Kohlrabi will thrive.

How to Plant Kohlrabi

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

4
successive plantings in your 169-day season

Sow every 5.1 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 31.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3" 3.3" 0" ✅ Rainfall sufficient
May 3" 4.8" 0" ✅ Rainfall sufficient
Jun 3" 5" 0" ✅ Rainfall sufficient
Jul 3" 4.7" 0" ✅ Rainfall sufficient
Aug 3" 3.6" 0" ✅ Rainfall sufficient
Sep 3" 3.7" 0" ✅ Rainfall sufficient
Oct 3" 3.1" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ramsey 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 ~632 GDD — county provides 1,943 GDD Excellent fit

Kohlrabi Planting Timeline — Ramsey County, MN

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest June 11 Jun 11 – Jul 16
Fall Sowing July 31 Jul 31 – Aug 14

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors
June Harvest
July Fall Sowing Harvest
August Fall Sowing
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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

169 days in Ramsey County

Growing Tips for Kohlrabi in Ramsey County

Direct sow Kohlrabi outdoors after April 23 in Ramsey County when soil has warmed and frost danger has passed.

Your generous 169.0-day season in Ramsey County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.

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 Ramsey County, MN?

Ramsey County is in Zone 5a with an average last frost of April 23. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ramsey County, MN?

Ramsey County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 9.

🌱

Your Ramsey County Garden Planner — Free

A 24-page printable planner built for Ramsey County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Ramsey County, MN. 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.