I'm having trouble getting tickets online just to see the garden. Am I able to come without a reservation and buy tickets there for the "day"?

Yes, the only time you need tickets ahead of time is for after hours events, like the holiday light show. Even members of the gardens need tickets for those type of events...

Yes no problem

Yes

Yes. You can buy either ticket or year pass.

Yes you can purchase a day pass or yearly pass

Yes you can

Yes, you can.👍

Yes you can wLk in any time to buy tickets