other ways to lay foliage

like select an area and fill it evenly with foliage. if I am laying thick foliage , it just lays in circles , if you overlap the other circles , then some areas are more dense . then when trying to fill in between circles it lays down less dense. from up on a hill overlooking a field I can see a bunch of big circles. Also why does it save the foliage right away. I cannot use undo for the foliage , because it saves the foliage on the map almost immediately.