When to plant hyssop in Pennsylvania
Pennsylvania spans USDA zones 5b–7b, so the right time to plant hyssop shifts by weeks across the state. The window to transplant seedlings 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 | Transplant out |
|---|---|---|---|---|
| Philadelphia | 7b | March 30 | November 17 | March 30 – April 13 |
| Pittsburgh | 6b | April 18 | October 28 | April 18 – May 2 |
| Allentown | 7a | April 20 | October 24 | April 20 – May 4 |
| Reading | 7a | April 14 | October 29 | April 14 – April 28 |
| Erie | 7a | April 26 | November 4 | April 26 – May 10 |
| Bethlehem | 7a | April 20 | October 24 | April 20 – May 4 |
| Scranton | 6b | April 23 | October 20 | April 23 – May 7 |
| Lancaster | 7a | April 19 | October 24 | April 19 – May 3 |
Hyssop in Pennsylvania: FAQ
When can I plant hyssop in Pennsylvania?
Across Pennsylvania, the time to transplant hyssop spans roughly March 30 in Philadelphia to May 15 in Hermitage, each following that city's local frost dates.
Does the hyssop planting date vary across Pennsylvania?
Yes. Pennsylvania publishes 86 cities with their own frost dates, so the right hyssop planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
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