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When to Plant Kohlrabi in Caldwell County, NC

Caldwell County, North Carolina Zone 7b May

This month in Caldwell County, North Carolina

May is a pivotal month for Caldwell County, North Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 10
Avg. first frost October 26
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: kohlrabi

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Bring in the kohlrabi

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • 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.

Caldwell County, North Carolina is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 26, giving you a growing season of approximately 199 days.

At an elevation of 1,108 feet, Caldwell County receives approximately 46 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°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.

Caldwell County, NC (Zone 7b) Moderate season
199 days
Last Spring Frost April 10
199 growing days
First Fall Frost October 26
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Caldwell County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (114 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: May 24 – Jun 28
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 29 – Jul 3
Safe Start (90%) ✓ Fits season (112 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 12 – Jul 17

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 Caldwell County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is moderate (2.4%). 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 199-day season

Sow every 5.1 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 17.

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 3.6" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3" 3.9" 0" ✅ Rainfall sufficient
May 3" 4.3" 0" ✅ Rainfall sufficient
Jun 3" 4.7" 0" ✅ Rainfall sufficient
Jul 3" 4.4" 0" ✅ Rainfall sufficient
Aug 3" 4" 0" ✅ Rainfall sufficient
Sep 3" 3.2" 0" ✅ Rainfall sufficient
Oct 3" 2.5" 0.5" 💧 Light watering
Nov 3.8" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Caldwell 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 ~1,004 GDD — county provides 3,631 GDD Excellent fit

Kohlrabi Planting Timeline — Caldwell County, NC

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Harvest May 29 May 29 – Jul 3
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
September
October
November
December
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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 7b

📆 Growing Season

199 days in Caldwell County

Growing Tips for Kohlrabi in Caldwell County

Direct sow Kohlrabi outdoors after April 10 in Caldwell County when soil has warmed and frost danger has passed.

With Caldwell 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 199.0-day season in Caldwell 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 Caldwell County, NC?

Caldwell County is in Zone 7b with an average last frost of April 10. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caldwell County, NC?

Caldwell County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 26.

🌱

Your Caldwell County Garden Planner — Free

A 24-page printable planner built for Caldwell County (Zone 7b). 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 Caldwell 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.