Mississippi Alluvial Plain

The Mississippi Alluvial Plain is the Delta, the flat wide floodplain the river built from Cairo down toward the Gulf, taking in Memphis, Greenville, Vicksburg, and Jonesboro. Soils are deep and heavy, the water table sits close to the surface, and ground that has not been leveled for row crops still floods. Natives like white wild indigo, rose-mallow, and dwarf palmetto are built for heavy wet soil and long humid heat.

Conditions: Deep heavy alluvial clay over a high water table, 48–56 inches of rain, hot humid summers and short mild winters.

Cities and areas: Memphis, Greenville, Vicksburg, Jonesboro, Clarksdale, Helena.