Compost improves soil health when mixed in the top 4-6 inches of soil. Adding compost will improve water and nutrient retention of sandy soils, as well as loosen compacted clay soils and make them more friable.
Work in no more than a two-inch layer of compost.
Be sure that compost is mature, has an earthy smell (no ammonia or rotten smell), and looks dark and crumbly with no recognizable feedstock.
Surface Mulch in Gardens & Landscape
Mulch provides protection from temperature extremes and slows moisture loss from soil. Mulch also provides some slow-release nutrients.
Use a maximum depth of three inches.
Start 3-4 inches away from a trunk.
Extend out to the dripline.
Compost, when used as lawn topdressing, retains moisture, supplies slow-release nutrients, and prevents soil compaction.
Be sure compost is very mature to avoid harming the lawn.
Use fine (screened) compost, raked over the lawn at a one-quarter inch depth.
It is best if the lawn is cored before applying compost.
Compost must be very mature to avoid injury to plants when used as a potting mix.