When to Plant Kohlrabi in Blair County, PA
Your May planting checklist for Blair County, Pennsylvania
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Blair County, Pennsylvania.
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Start kohlrabi indoors
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
June will be here before you know it — start on
- 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.
Blair County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 25 and the first fall frost is October 19, giving you a growing season of approximately 177 days.
At an elevation of 41 feet, Blair County receives approximately 43.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Kohlrabi during the growing season.
Blair County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.8
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 Blair County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (5.2–6.8) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Blair County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.1%). 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 15 to harvest before frost.
For a dedicated fall crop, sow by Aug 10.
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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.8" | 0" | ❄️ Dormant |
| Apr | 3" | 4" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.1" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Blair 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 — Blair County, PA
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | April 25 | Apr 25 – May 9 |
| Direct Sow | April 11 | Apr 11 – May 2 |
| Harvest | June 13 | Jun 13 – Jul 18 |
| Fall Sowing | August 10 | Aug 10 – Aug 24 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| 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
177 days in Blair County
Growing Tips for Kohlrabi in Blair County
Direct sow Kohlrabi outdoors after April 25 in Blair County when soil has warmed and frost danger has passed.
Your generous 177.0-day season in Blair 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 Blair County, PA?
Blair County is in Zone 6b with an average last frost of April 25. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Blair County, PA?
Blair County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 25 and first fall frost is October 19.
Your Blair County Garden Planner — Free
A 24-page printable planner built for Blair 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.