The Sebring Rock Garden has generous amounts of scree, a very stony soil composed mostly of clean rock fragments with lesser amounts of compost and even less sandy loam. In this case the rock fragments are clean scoria (a lava from the Cascades) with a top dressing of washed grit. The grit is used for the same purpose as any garden mulch: to control weeds, conserve moisture, and to enhance the appearance. Weeding is a breeze in this garden and the rock-loving plants soon outpace the weeds. Grit is chosen that more naturally "matches" the larger rocks in the garden. A nice deep scree promotes good drainage and stays cool on the hottest day. Some plants will root deeply into the natural heavier soil beneath, but their crowns and more delicate roots still benefit greatly from the excellent drainage that scree provides.