The transition zone is the grass-growing region that cuts through the middle of the U.S. where warm-season and cool-season grasses can grow. This region presents some unique lawn care challenges, as warm-season grasses go dormant in the winter, while cool-season grasses struggle in the summer. Most of Arkansas is in the transition zone. Only about the lower third of the state, including the southern portions of the Gulf Coastal Plain and the Mississippi Alluvial Plain, is too warm for cool-season grasses and so is not part of the transition zone.