Previously, I was attaching tape, glue dots, etc directly to the balloons and pressing them onto the wall. That failed. After a lot of experimenting, I discovered if I attach a size 160 balloon to the balloon flower and used coloured electrical plastic tape, it stayed on the wall for over 4 hours.
Details on what I did:
I cut a size 160 balloon and attached it to the balloon flower by wrapping it around the balloon flower a few times. After attaching the 160 balloon to the balloon flower, I attached the tape onto the end of the 160 balloon, then I attached that part to the wall by pressing on the tape against the wall. I also made sure there was not a lot of tension between the end of the 160 balloon where it had the tape attached and the wall itself so the tape would not be pulled off the wall.
The attached photos shows what I did.