if you're going for something make-believe, it pays to go the extra mile to plan & execute the entire concept. the aim is to make viewers do a double-take and say, "hey! that's not a real flower!"
build a set around your metal flowers. what accompanies a flower? leaves, vase, soil, etc. lighting? soft window light? etc.
the trick is to bring it across with sophistication. it's all too easy to end up with something corny.