It looks like the tickets are not for a particular day.
In addition, if I arrive on an afternoon of one day, can I go to the show the following morning?
You are correct. The Flower show tickets are good for the run of the Show, not for a particular day. Opening and closing hours vary.
Please note that the hours described as PHS Members' Preview are NOT public hours. They are just for PHS Members at the Household level and higher (Individual, Dual and Family members are not elegible for the Members' Preview).
If you purchase tickets in advance, yes, you will be admitted to the Show during the public hours any day during the run of the Show. An adult online ticket purchased by March 4 is $27.00 plus a $1.00 service fee. A ticket at the door purchased March 5 - 13 will cost $34.00.
Tickets are good for one day only. No, it is not possible to split your ticket to go the afternoon of one day and the following morning. You would either need two Flower Show tickets for those two days or you could purchase a PHS membership that gives you two tickets.
Thanks and enjoy the Show!