You don’t own the land when you “buy’ a grave. You are buying a “right of burial”. The cemetery can dictate what may be placed on the grave up to and including the memorial. If they don’t like anything placed on a grave up to and including, say, 2500.00 dollars worth of granite memorial, they can remove it (Ive seen it done). It likely says this somewhere on the cemetery in questions website.
“You don’t own the land when you “buy’ a grave. You are buying a “right of burial”. The cemetery can dictate what may be placed on the grave up to and including the memorial.”
You buy rights to the property for your exclusive use. The cemetery can only dictate what is placed on the grave as stated in the deed. If no restrictions are listed, you are free to use any memorial you choose.