Help! How do I hide an ugly metal plate in the grass?

My parents have moved to Leisure World and they have a great end unit but just as you walk up towards the front, there is an unsightly large rectangular green metal plate in the grass. It must be for water or sewer access.

I thought about buying two mats (the size of the metal plate) and putting a potted rose tree on top of the mats (which are in the grassy area) along the walkway but I'm not sure if that's the best idea.

Can someone give me some ideas to hide this icky-poo thing? I've looked online and found the fake granite rocks :-( but would love to hear what others have done.

Thank you so much!

Nancy
(Happy Girl)