In MLB, there are three stadiums still in use (2008 season) that would have to use artificial turf instead of grass: Minnesota, Tampa Bay, Toronto. These three stadiums are the last domes in use, and in the case of Minnesota and Tampa Bay there are plans to replace their stadiums in the next five years.
Grass, artificial turf
No some football fields use natural grass. Most football stadiums are switching to artificial turf because it is cheaper and easier to maintain.
The most well-known use for artificial grass is for use in a variety of sports venues. Football and baseball stadiums have long used artificial grass, but more and more commercial and residential customers have been using it as well.
there are 20 stadiums with natural grass left
Some stadiums have grass and some stadiums have turf.
Natural grass, artificial turf, and the new manufactured turf which looks like grass but made out of rubber.
Baseball games are played on both natural grass surfaces and artificial turf.
Grass
Only two ballparks in MLB still use artificial turf. Rogers Center (Toronto Blue Jays) and Tropicana Field (Tampa Bay Rays).
Astroturf is a type of artificial turf used to mimic grass. While not the same as grass, the cost of laying AstroTurf, especially in indoor stadiums, is much cheaper then laying natural turf and maintaining it.
Both Stadiums have been grass.
Most indoor stadiums use AstroTurf and outdoor stadiums use natural grass. Also most use green grass!:)