A Growing Stop Sign

On my way to the metro this morning, at the corner of New Hampshire Ave & Corcoran St NW I saw two stop signs and a parking regulation sign with these green "leaves" taped (with duct tape) to the poles holding the signs up. I don't remember seeing these yesterday. I have no idea what they are for, but they struck me as odd.

Update:hungeegirl says, "i think those leaves were put there as a 'happy spring' sort of thing. i think the only intent is to make the stop sign look like a flower."