When to Plant Kohlrabi in Hamilton County, NY
Top priorities for Hamilton County, New York gardeners in May
Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.
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Get kohlrabi in the ground
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Sow kohlrabi where they'll grow
Your soil is 50°F — warm enough for these to germinate without babying.
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.
Hamilton County, New York is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 28, giving you a growing season of approximately 131 days.
At an elevation of 959 feet, Hamilton County receives approximately 49.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Kohlrabi to ensure they mature before fall.
Hamilton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.2
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 Hamilton County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (5.2–6.2) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Hamilton 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 (3.4%). Annual compost additions will help Kohlrabi.
How to Plant Kohlrabi
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Jul 25 to harvest before frost.
For a dedicated fall crop, sow by Jul 06.
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" | 0" | ❄️ Dormant |
| Feb | — | 2.9" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | — | 4.8" | 0" | ❄️ Dormant |
| May | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Oct | — | 3.9" | 0" | ❄️ Dormant |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Hamilton 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 — Hamilton County, NY
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Direct Sow | May 13 | May 13 – Jun 3 |
| Harvest | July 8 | Jul 8 – Aug 12 |
| Fall Sowing | July 6 | Jul 6 – Jul 20 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | 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 4b
📆 Growing Season
131 days in Hamilton County
Growing Tips for Kohlrabi in Hamilton County
Direct sow Kohlrabi outdoors after May 20 in Hamilton 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 Hamilton County, NY?
Hamilton County is in Zone 4b with an average last frost of May 20. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hamilton County, NY?
Hamilton County, New York is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 28.
Your Hamilton County Garden Planner — Free
A 24-page printable planner built for Hamilton County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.