• Good groundcover is difficult in clay soil.mossy groundcover image by Undy from Fotolia.com
  
  Few groundcover plants outside the sumac family will tolerate clay soils, according to Mary H. Meyer and Michael E. Zins of the University of Minnesota. Successful groundcover necessitates the use of appropriate soil types as growth mediums. Groundcovers that flourish are selected for individual garden conditions. An evergreen groundcover does not die back to the earth and bare soil in winter elements, reports the University of Illinois. Groundcovers are either herbaceous or woody plants.
  
  

Sumacs

• Sumacs are woody plant groundcovers. Several sumacs tolerate most any soil, state Meyer and Zins. Fragrant sumac, skunkbush sumac and both smooth and staghorn sumacs tolerate most all dry soils and produce attractive foliage. All sumacs other than the skunkbush variety color brightly in autumn. Sumac height ranges from 2 to 10 feet depending on plant chosen and area planted. Most sumacs are spread through transplantation or root cuttings. Most sumacs tolerate hardiness zones 4 to 8 but some can withstand zones 3 to 9.
  
  

Barberry and Chokeberry

• Barberry and chokeberry are both wood plant groundcovers. Both plants tolerate most any soil and produce flowers and fruits. The yellow flowers and red fruits of barberry plants persist through over the winter, according to Meyer and Zins. Both plants cover well on dry banks. Barberry achieves a height of 6 to 8 feet and chokeberry tops out less than 2 feet tall. Chokeberry is more widely available than barberry. Both plants are spread through transplantation. Barberry and chokeberry withstand zone 4 to 8 well, but some variants will tolerate zones 3 to 9.
  
  

Crown Vetch

• Crown vetch is an herbaceous plant that tolerates clay soils, reports Meyer and Zins. Crown vetch can withstand dry infertile soils and may show winter injury. This herbaceous groundcover possesses attractive flowers and is long lasting but slow to establish. A single crown vetch can cover 6 feet in 2 to 3 years and usually achieves a height no greater than 3 feet tall. Crown vetch is widely used for erosion control, but some states consider it an invasive species, so check your state's guidelines before planting. Crown vetch withstands zones 4 to 8.