D.G. stands for decomposed granite, a paving material enjoying a renaissance, especially in water-efficient gardens where less space is given to thirsty lawns. Popular in the 1920s and ‘30s on large estates as an inexpensive covering for broad paths, decomposed granite is now being used for large and small walkways and even patios by some of today’s most daring landscape architects and designers.
Suggesting the use of D.G. takes guts because some people think it looks suspiciously like dirt, and many hillside gardeners are already gardening in a similar-looking soil that crumbles from cuts and cliffs. But D.G. is more like sand or rock than dirt; it makes a harder surface with more body if one part dry cement is mixed with seven parts dry D.G.
D.G. is not simply spread over the ground: It is applied in 3- to 6-inch-deep layers that are thoroughly compacted with a heavy lawn roller. Paths are usually given a slight crown so that they will better shed water. You’ll find D.G. surprisingly comfortable to walk on (though not in bare feet). Have the D.G. end a few feet away from the house so it has time to fall away from shoes. Otherwise, granite can be tracked indoors.
Garden designers like the natural ocher color of D.G. and the casual look it gives a garden, especially to a garden that would otherwise be formal in plan. They also appreciate the material’s flexibility; it is quite easy to change the size or shape of a D.G. path.