You have several choices for this meeting.
If you want a 30-minute DSLR Macro Photography class in addition to exploring the gardens with us, go to Uniquephoto.com and sign up. That class is $68, and will fill up.
If you just want to meet us there and we will walk around as a group or split up and meet at certain times, go to tickets.longwood.org and make sure to buy an EVENT TICKET for Fireworks and Fountains, or you will have to leave at 3. The event ticket includes all-day admission, so you are free to arrive any time you like. Let me know what time you plan to arrive, and I'll let you know what time to rendezvous. Here's the url for the event we're attending: