If we arrive by train (Amtrak), how close is the train station to the flower show? I think the 30st station would be the closest?
Amtrak takes you to 30th Street Station. From there, you will need to switch to the SEPTA regional rail platform and take any eastbound SEPTA rail train to Jefferson Station (formerly called Market East Station). You don't need to buy a SEPTA ticket, just be prepared to show your Amtrak ticket to the conductor if asked. At Jefferson Station, follow signs to the Flower show -- you can enter without exiting to the street -- it's right there!