City	Sow outdoors	Last frost
Philadelphia	Apr 20 to May 4	Mar 30
Pittsburgh	May 9 to May 23	Apr 18
Allentown	May 11 to May 25	Apr 20
Reading	May 5 to May 19	Apr 14
Erie	May 17 to May 31	Apr 26
Bethlehem	May 11 to May 25	Apr 20
Scranton	May 14 to May 28	Apr 23
Lancaster	May 10 to May 24	Apr 19
Levittown	May 12 to May 26	Apr 21
Harrisburg	May 6 to May 20	Apr 15
York	May 17 to May 31	Apr 26
Wilkes-Barre	May 14 to May 28	Apr 23
Altoona	May 16 to May 30	Apr 25
State College	May 11 to May 25	Apr 20
Penn Hills	May 7 to May 21	Apr 16
Norristown	Apr 29 to May 13	Apr 8
Chester	Apr 20 to May 4	Mar 30
Mount Lebanon	May 9 to May 23	Apr 18
Bethel Park	May 9 to May 23	Apr 18
Easton	May 9 to May 23	Apr 18
Hazleton	May 21 to Jun 4	Apr 30
Drexel Hill	Apr 23 to May 7	Apr 2
Monroeville	May 13 to May 27	Apr 22
Williamsport	May 16 to May 30	Apr 25
Lebanon	May 11 to May 25	Apr 20
Plum	May 7 to May 21	Apr 16
King of Prussia	Apr 29 to May 13	Apr 8
Chambersburg	May 9 to May 23	Apr 18
Pottstown	May 11 to May 25	Apr 20
Carlisle	May 14 to May 28	Apr 23
Allison Park	May 7 to May 21	Apr 16
New Castle	May 21 to Jun 4	Apr 30
Murrysville	May 13 to May 27	Apr 22
Baldwin	May 9 to May 23	Apr 18
Phoenixville	May 9 to May 23	Apr 18

Questions

When should I plant okra in Pennsylvania?

In Philadelphia, sow outdoors from April 20 to May 4. Across Pennsylvania the window opens between April 20 and May 21, depending on the local last frost.

How is this date worked out?

Sow outdoors 3–5 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.