Everyone loves a beautiful lawn, but one of the most detrimental things to grass is shade.  When your trees grow large and beautiful, you have an opportunity to use some shade loving groundcover rather than trying to grow grass in those shady areas.  Shade loving plants used in mass can be a monoculture of all one kind, or drifts of different types of plants that would be suitable for an area.  Some groundcovers are very short and there are also plants that can support some light foot traffic.  Other shade loving groundcovers can be a bit taller and do an excellent job of holding the soil, all adding an excellent design element to your landscape.