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When to Plant Kohlrabi in Alamance County, NC

Alamance County, North Carolina Zone 8a May

Your May planting checklist for Alamance County, North Carolina

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Alamance County, North Carolina.

Avg. last frost April 2
Avg. first frost November 3
Soil temp (4") 69°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 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.

  2. Bring in the kohlrabi

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • 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.

Alamance County, North Carolina is in USDA Zone 8a. The average last spring frost is April 2 and the first fall frost is November 3, giving you a growing season of approximately 215 days.

At an elevation of 571 feet, Alamance County receives approximately 42.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92°F, providing good warmth for Kohlrabi during the growing season. Clay soil retains moisture well for Kohlrabi, but amend with compost to improve drainage and prevent root rot.

Alamance County, NC (Zone 8a) Long season
215 days
Last Spring Frost April 2
215 growing days
First Fall Frost November 3

Alamance County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (134 days to spare)
Start indoors: Feb 17 Transplant: Mar 24 🍅 Harvest: May 12 – Jun 16
Recommended (50%) ✓ Fits season (131 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: May 21 – Jun 25
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 9 – Jul 14

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 Alamance County

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

Soil pH

Your soil pH (5.6–6.3) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Kohlrabi.

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

5
successive plantings in your 215-day season

Sow every 5.1 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 25.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/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 3.9" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 3" 3.5" 0" ✅ Rainfall sufficient
May 3" 3.7" 0" ✅ Rainfall sufficient
Jun 3" 3.4" 0" ✅ Rainfall sufficient
Jul 3" 4.6" 0" ✅ Rainfall sufficient
Aug 3" 4.3" 0" ✅ Rainfall sufficient
Sep 3" 3.2" 0" ✅ Rainfall sufficient
Oct 3" 2.5" 0.5" 💧 Light watering
Nov 3" 3.1" 0" ✅ Rainfall sufficient
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Alamance 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 ~1,045 GDD — county provides 4,085 GDD Excellent fit

Kohlrabi Planting Timeline — Alamance County, NC

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 19 Mar 19 – Apr 9
Harvest May 21 May 21 – Jun 25
Fall Sowing August 25 Aug 25 – Sep 8

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

215 days in Alamance County

Growing Tips for Kohlrabi in Alamance County

Direct sow Kohlrabi outdoors after April 02 in Alamance County when soil has warmed and frost danger has passed.

With Alamance County's clay soil (33% clay), work in 3-4 inches of compost before planting Kohlrabi. Avoid tilling when soil is wet to prevent compaction.

Your generous 215.0-day season in Alamance 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 Alamance County, NC?

Alamance County is in Zone 8a with an average last frost of April 2. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alamance County, NC?

Alamance County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 2 and first fall frost is November 3.

🌱

Your Alamance County Garden Planner — Free

A 24-page printable planner built for Alamance County (Zone 8a). 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 Alamance County, NC. 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.