Would you say "I was reading on the Reading Garden" or "I was reading in the Reading Garden"?

It is an open area outside with benches where you can sit and read on a nice day. I have to write a description on our library's website and we are all divided is to which is the proper preposition to us. It will be available to the public and I don't want to make us look like idiots (even half of us are).

Thank you for any help you can give me.

Glory

I'd say "... in the garden... "

I would say "in" also. It would be different if it was a deck or a patio. Then you could use "on" and it would make sense.

I agree. "In."