When to Plant Kohlrabi in Harnett County, NC
This month in Harnett County, North Carolina
May is a pivotal month for Harnett County, North Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Begin indoor sowing: kohlrabi
You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.
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Basket week: kohlrabi
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
A few tasks this May that'll pay off in June
- First harvests: 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.
Harnett County, North Carolina is in USDA Zone 8a. The average last spring frost is March 29 and the first fall frost is November 6, giving you a growing season of approximately 222 days.
At an elevation of 613 feet, Harnett County receives approximately 53.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.
Harnett County Soil Profile
Soil Type
Clay Loam
Soil pH
5.5-6.6
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 Harnett County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (5.5–6.6) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.
Soil Texture
The clay loam soil in Harnett 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 (2.8%). Annual compost additions will help Kohlrabi.
How to Plant Kohlrabi
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Sep 02 to harvest before frost.
For a dedicated fall crop, sow by Aug 28.
Plant Water Budget
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 | — | 4.6" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | 3" | 5" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 4.6" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 5" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Harnett 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 — Harnett County, NC
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 22 | Feb 22 – Mar 8 |
| Transplant Outdoors | March 29 | Mar 29 – Apr 12 |
| Direct Sow | March 15 | Mar 15 – Apr 5 |
| Harvest | May 17 | May 17 – Jun 21 |
| Fall Sowing | August 28 | Aug 28 – Sep 11 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors 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: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
222 days in Harnett County
Growing Tips for Kohlrabi in Harnett County
Direct sow Kohlrabi outdoors after March 29 in Harnett County when soil has warmed and frost danger has passed.
With Harnett County's clay soil (27% clay), work in 3-4 inches of compost before planting Kohlrabi. Avoid tilling when soil is wet to prevent compaction.
Your generous 222.0-day season in Harnett 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
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Check more plant combinations with our Companion Planting Checker →
Kohlrabi in Other Locations
Frequently Asked Questions
When should I plant Kohlrabi in Harnett County, NC?
Harnett County is in Zone 8a with an average last frost of March 29. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harnett County, NC?
Harnett County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 29 and first fall frost is November 6.
Your Harnett County Garden Planner — Free
A 24-page printable planner built for Harnett 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.