Q. Buses or Trains available to PHS Philadelphia Flower Show?
The trip organizers don't necessarily tell us where they are coming from or when. But you are correct, it looks like Klein's Bus transportation is coming to the Flower Show. Not aware of any train service.
There is also Greyhound Bus from Reading or Pottstown to Philadelphia. The bus station is very close to the Convention Center.
Hope this helps and enjoy the Show!