When to Plant Kohlrabi in Jefferson County, IN
Your May planting checklist for Jefferson County, Indiana
A quick May briefing for Jefferson County, Indiana gardeners — what's urgent, what's next, and what can wait.
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Get kohlrabi seeds going inside
Label every cell. You will absolutely forget which is which otherwise.
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Start harvesting kohlrabi
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
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.
Jefferson County, Indiana is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.
At an elevation of 1,010 feet, Jefferson County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Kohlrabi during the growing season.
Jefferson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
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 Jefferson County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Jefferson County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Kohlrabi will thrive.
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 Aug 17 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 3" | 3.1" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 2.8" | 0.2" | 💧 Light watering |
| Oct | 3" | 2.2" | 0.8" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jefferson 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 — Jefferson County, IN
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 12 | Aug 12 – Aug 26 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 | — |
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 6b
📆 Growing Season
194 days in Jefferson County
Growing Tips for Kohlrabi in Jefferson County
Direct sow Kohlrabi outdoors after April 10 in Jefferson County when soil has warmed and frost danger has passed.
Your generous 194.0-day season in Jefferson 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
Check more plant combinations with our Companion Planting Checker →
Kohlrabi in Other Locations
Frequently Asked Questions
When should I plant Kohlrabi in Jefferson County, IN?
Jefferson County is in Zone 6b 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 Jefferson County, IN?
Jefferson County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 21.
Your Jefferson County Garden Planner — Free
A 24-page printable planner built for Jefferson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.