When to Plant Kohlrabi in Carroll County, NH
Your May planting checklist for Carroll County, New Hampshire
Here's what deserves your attention in Carroll County, New Hampshire this month. Everything below is tailored to Zone 5a and timed around your local frost dates.
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Transplant kohlrabi outside
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
To set up a strong June, finish these tasks
- Starting indoors: kohlrabi
- 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.
Carroll County, New Hampshire is in USDA Zone 5a. The average last spring frost is May 9 and the first fall frost is October 6, giving you a growing season of approximately 150 days.
At an elevation of 433 feet, Carroll County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Kohlrabi to ensure they mature before fall.
Carroll County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.5
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 Carroll County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (5.2–6.5) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Carroll County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). 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 Aug 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 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 | — | 3.3" | 0" | ❄️ Dormant |
| Feb | — | 2.8" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.1" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Carroll 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 — Carroll County, NH
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | June 27 | Jun 27 – Aug 1 |
| Fall Sowing | July 28 | Jul 28 – Aug 11 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| 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: too_acidic
🗺️ USDA Zone
Zone 5a
📆 Growing Season
150 days in Carroll County
Growing Tips for Kohlrabi in Carroll County
Direct sow Kohlrabi outdoors after May 09 in Carroll County when soil has warmed and frost danger has passed.
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 Carroll County, NH?
Carroll County is in Zone 5a with an average last frost of May 9. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Carroll County, NH?
Carroll County, New Hampshire is in USDA Hardiness Zone 5a. The average last spring frost is May 9 and first fall frost is October 6.
Your Carroll County Garden Planner — Free
A 24-page printable planner built for Carroll County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.