When to Plant Kohlrabi in New Castle County, DE
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.
New Castle County, Delaware is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.
At an elevation of 415 feet, New Castle County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Kohlrabi during the growing season.
New Castle County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-7.1
Drainage
Well Drained
Monthly Watering Guide for Kohlrabi
Kohlrabi needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Kohlrabi Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 3.4" | 0" | ❄️ Dormant |
| Dec | — | 2.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in New Castle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kohlrabi Planting Timeline — New Castle County, DE
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 23 | Mar 23 – Apr 13 |
| Harvest | May 25 | May 25 – Jun 29 |
| Fall Sowing | August 22 | Aug 22 – Sep 5 |
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 | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
208 days in New Castle County
Growing Tips for New Castle County
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 New Castle County, DE?
New Castle County is in Zone 7a with an average last frost of April 6. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is New Castle County, DE?
New Castle County, Delaware is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 31.
Plan Your Garden with Confidence
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