RE: do deer like tall grass or mowed grass better?
mowed-food
tall- cover
all depends what you're looking to do.....but if you meant which would attract/hold more deer, that may be up for a debate....while food may lure in some deer, cover will hold them, but why would they come to your land simply for cover, if another area has both cover and food.
I'd give them everything they wanted if I was managing some land.