When to plant sunflower in Pennsylvania
Pennsylvania spans USDA zones 5b–7b, so the right time to plant sunflower shifts by weeks across the state. The window to sow seed directly outdoors runs from about March 30 in Philadelphia to May 15 in Hermitage — below are local dates for 86 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Philadelphia | 7b | March 30 | November 17 | March 30 – April 20 |
| Pittsburgh | 6b | April 18 | October 28 | April 18 – May 9 |
| Allentown | 7a | April 20 | October 24 | April 20 – May 11 |
| Reading | 7a | April 14 | October 29 | April 14 – May 5 |
| Erie | 7a | April 26 | November 4 | April 26 – May 17 |
| Bethlehem | 7a | April 20 | October 24 | April 20 – May 11 |
| Scranton | 6b | April 23 | October 20 | April 23 – May 14 |
| Lancaster | 7a | April 19 | October 24 | April 19 – May 10 |
Sunflower in Pennsylvania: FAQ
When can I plant sunflower in Pennsylvania?
Across Pennsylvania, the time to direct-sow sunflower spans roughly March 30 in Philadelphia to May 15 in Hermitage, each following that city's local frost dates.
Does the sunflower planting date vary across Pennsylvania?
Yes. Pennsylvania publishes 86 cities with their own frost dates, so the right sunflower planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does sunflower take to grow in Pennsylvania?
Sunflower takes about 70–100 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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