People often get wet spots in their yard where the water collects or cannot drain fast enough. There are several solutions to this problem, and you should try some of the simpler ones first. Try to find where the water is coming from before you take any action as well, it may just be that your downspout needs to be re-directed from a low spot in your yard.
Ground cover is plants that fill in an area of your landscaping. These can be good in certain areas where you would like low maintenance after the plants are established. There are a variety of ground covers that can be planted in areas ranging from mostly shaded to mostly sunny. Sweet Woodruff, Hellebore, Ivy, Lily of the Valley, Pachysandra, European Ginger, Ajuga, Vinca, Sedum, and Isotoma are some different groundcovers that can be used in the Midwest area. Ground cover is useful for shaded areas under trees where you don’t want to have to do a lot of maintenance, or areas with a slight slope that would be difficult to mow, or to fill in beds around large shrubs.