When to Plant Kale in Pennsylvania
Published: April 24, 2026
Pennsylvania gardeners in Zone 6a have a 31-week growing season for kale (March 30 to November 1). Pennsylvania's spring and fall windows both work well for kale — some gardeners plant both successions for a long harvest. This guide gives exact dates for Pennsylvania based on your local frost calendar.
Kale Planting Dates for Pennsylvania
| Start seeds indoors | February 23–March 2 |
| Last frost (average) | March 30 |
| Transplant outdoors | March 2–12 |
| Direct sow outdoors | March 2–12 |
| Expect first harvest | April 26 – May 16 |
| Fall crop start | September 6–16 |
| Fall harvest | October 31 |
| First fall frost (average) | November 1 |
Dates above assume Zone 6a, the most common zone in Pennsylvania. Gardeners in cooler Scranton (Zone 5b) plant 1–2 weeks later; warmer Philadelphia (Zone 6a) can plant 1–2 weeks earlier.
⚠ Plant kale 3–5 weeks before last frost for spring. Best planted in late summer (6–8 weeks before first fall frost) for fall/winter harvest. Frost sweetens the flavor.
Growing Kale in Pennsylvania's Climate
Pennsylvania's moderate Zone 6a climate is well-suited to kale with minimal special accommodation. The standard transplant calendar works as written, and harvest windows line up with what seed packets recommend without adjustment.
Succession planting extends your kale harvest significantly in Pennsylvania. A second planting 3 to 4 weeks after the first gives you a backup in case of pest pressure and extends the total harvest window into early fall.
Common kale pests to watch for in Pennsylvania include Cabbage Worm and Cabbage Looper. The first line of defense is companion planting: Onion and Garlic planted nearby discourage several of these pests by confusing host-plant identification or repelling adults before they can lay eggs. Weekly garden walks in the early morning catch problems when they're still manageable.
Kale Garden Calendar for Pennsylvania
| Month | Task | Notes |
|---|---|---|
| January | — | Dormant season |
| February | Start seeds indoors | Use grow lights; warm soil to 70–75°F for best germination |
| March | Transplant outdoors | Soil temp must be 40°F+; nighttime lows above 50°F |
| April | First harvest window opens | Kale begins producing 55–75 days after transplant |
| May ← | Watch for bolting | Harvest promptly; spring heat arrives quickly |
| June | — | Dormant season |
| July | — | Dormant season |
| August | — | Dormant season |
| September | Fall crop planting | Transplant or direct sow for fall harvest before frost |
| October | — | Dormant season |
| November | First frost approaches | Harvest remaining kale; cover plants on frost nights |
| December | — | Dormant season |
Kale Growing Tips for Pennsylvania Gardeners
- •Harvest outer leaves first using the cut-and-come-again method; the central growing point will produce for months.
- •Kale leaves become sweeter after the first frost as plants convert starches to sugars — wait for cold nights for best flavor.
- •Pennsylvania's moderate climate supports succession planting — sow new transplants or seeds every 3 weeks during spring to extend the harvest window into fall.
- •Use floating row covers to block cabbage white butterflies from laying eggs on plants.
Companion Planting for Kale in Pennsylvania
In Pennsylvania's moderate climate, planting kale with Onion and Garlic helps deter pests and improve soil. Avoid planting near Tomato and Strawberry, which inhibit kale growth through root chemistry or shared pest pressure. See the full kale companion planting guide for the complete list.
Kale Planting Dates by City in Pennsylvania
Top cities in Pennsylvania — select for city-level frost dates and planting calendars.
Frequently Asked Questions
When should I plant kale in Pennsylvania?
In Pennsylvania (Zone 6a), start kale seeds indoors around February 23–March 2 and transplant outdoors around March 2–12 — 4 weeks before the state's average last frost of March 30.
What is the last frost date in Pennsylvania?
Pennsylvania's average last frost date is March 30 in the state's most common Zone 6a. Frost dates vary by city — higher elevations and northern counties run 1 to 3 weeks later than the state average. See the city list below for city-level frost dates.
Can I grow kale year-round in Pennsylvania?
kale is a cool-season crop in Pennsylvania, with spring and fall windows. Summer heat bolts the plants before they can produce a harvestable crop. Succession planting every 2–3 weeks stretches the harvest window.
What kale varieties grow best in Pennsylvania?
For Pennsylvania's Zone 6a, consult a local nursery or extension office for kale variety recommendations.
When do I start kale seeds indoors in Pennsylvania?
Start kale seeds indoors in Pennsylvania around February 23–March 2, which is 5 weeks before the state's average last frost of March 30. Use grow lights and keep soil temperatures at 70–75°F for fastest germination.