06/09/2016
Lawns mowed at 3.5 or 4 inches out-compete weeds, tolerate grubs and look just as good as lawns mowed at 2.5 inches.
http://msue.anr.msu.edu/uploads/files/Mow_high.pdf
How high? 3.5-inch height or higher.
How often?Let the grass be your guide.
What about the clippings? Leave them.
http://www.gardening.cornell.edu/homegardening/sceneec8a.html