Tyson,
Thanks for the response. Following are the answers to your questions:
– The grate will probably be about 5′ x 5′
– The type of tree is not final but it will be a xeric, hardy ornamental
– Staking will most likely be installed
– The installation will be a concrete plaza for pedestrian use
– The project is private
– The grates do not have to be ADA
I look forward to your response.