As a copywriter, I personally enjoy the sarcasm of this sign. But, in the interest of effectiveness, I would recommend a more direct approach. Maybe we should take this to focus-group testing.
If for some crazy reason you can’t make out what this sign says, it reads:
“Patches of Brown”
Brought to you by the generous donation of
PLEASE Walk your dog elsewhere. Thank you.
Taken at the corner of Chicago Ave. and Larabee