Not exactly. There are many trains from Shanghai to Suzhou. There are many bullet trains (about half a hour to Suzhou) also. Most of the trains to Suzhou are leaving from Shanghai Railway Station. Bus You 1, You2, You 5 can take you to the garden from Suzhou Railway Station and get off at Suzhou Museum, then walk about ten minutes to the garden. Or take a taxi directly, which costs about the starting price.