I hold white rocks surrounded by a shady flower bed. How can I verbs them? The rocks are black, green and dirty. I want to clean...

The rocks are black, green and dirty. I want to clean them lacking hurting my flowers. Please give me some philosophy! Thanks!
Anyone know where on earth I can find...
Answers:    A mild soap and water solution will verbs rocks and it is good for plants and soil.
Blackberry's?
create a very questionable solution of bleach and water and sprinkle it over the rocks. The bleach will soon assassinate the moss on the rocks.