When to Plant Napa Cabbage in Allegheny County, PA
What to do in May
A quick May briefing for Allegheny County, Pennsylvania gardeners — what's urgent, what's next, and what can wait.
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Get napa cabbage seeds going inside
These need a head start before your last frost (April 25). Sow into cells now so you're ready to transplant in a few weeks.
A few tasks this May that'll pay off in June
- First harvests: napa cabbage
Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.
Allegheny County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 25 and the first fall frost is October 28, giving you a growing season of approximately 186 days.
At an elevation of 118 feet, Allegheny County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Napa Cabbage during the growing season.
Allegheny County Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.5
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 Allegheny County
How your county's soil matches Napa Cabbage's growing requirements.
Soil pH
Your soil pH (5.0–6.5) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Allegheny County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.8%). Annual compost additions will help Napa Cabbage.
How to Plant Napa Cabbage
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Napa Cabbage
Sow every 6.3 weeks. Last sowing by Aug 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 19.
Plant Water Budget
Monthly Watering Guide for Napa Cabbage
Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Napa Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3" | 0" | ❄️ Dormant |
| Feb | — | 3.1" | 0" | ❄️ Dormant |
| Mar | — | 3.7" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.2" | 3.3" | 🚿 Regular watering |
| May | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| Jun | 6.5" | 3.5" | 3" | 💧 Light watering |
| Jul | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Aug | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Sep | 6.5" | 3" | 3.5" | 🚿 Regular watering |
| Oct | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Allegheny County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Napa Cabbage 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.
Napa Cabbage Planting Timeline — Allegheny County, PA
Napa Cabbage 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 20 | Jun 20 – Jul 25 |
| Fall Sowing | August 19 | Aug 19 – Sep 2 |
Plant 1" deep · 15" apart · Rows 24" 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 | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6b
📆 Growing Season
186 days in Allegheny County
Growing Tips for Napa Cabbage in Allegheny County
Direct sow Napa Cabbage outdoors after April 25 in Allegheny County when soil has warmed and frost danger has passed.
Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Napa Cabbage in Other Locations
Frequently Asked Questions
When should I plant Napa Cabbage in Allegheny County, PA?
Allegheny County is in Zone 6b with an average last frost of April 25. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Allegheny County, PA?
Allegheny County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 25 and first fall frost is October 28.
Your Allegheny County Garden Planner — Free
A 24-page printable planner built for Allegheny 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.