Uses for Compost in Horticulture
Compost can be mixed with sand, clay, aged sawdust, and other materials to create an enriched mix for landscape beds or raised-bed gardens. Compost should be no more than 30 percent of the total mix. Use a high quality mature compost to avoid nutrient competition with plants.
Container mixes Like bedding mixes, compost is a beneficial ingredient in potting media, used up to 30 percent of the total mix. It is an excellent substitute for peat moss. The NPK content of compost can also reduce the need for chemical fertilizers.
Foundation plantings Excavated areas around the foundation of new buildings are backfilled when construction is complete, but these planting zones may contain rubble, residues of toxic chemicals, and other undesirable substances. Removing the backfill and replacing it with a soil/compost mix will improve soil structure and give foundation plantings a healthier start.
Mulch/weed control Two or more inches of compost can be used alone or in conjunction with conventional mulch products to keep root zones cool, conserve moisture, and act as a slow-release fertilizer, encouraging beneficial soil microbes. For a weed barrier, double or triple the depth of compost can be used, placed on top of a thick layer of newspapers, to replace geomembrane weed barriers.
Trees and shrubs Mix well aged compost with the native soil and use as backfill when planting trees and shrubs. Immature composts may cause settling and young root disturbance. Seasonally, top dress with compost to the drip line and rake into the soil.
Turf and pasture management To establish new turf areas (lawns, recreation fields, golf courses), apply compost prior to seeding or sodding and work into the soil. Seasonally, top dress with compost and rake into the soil. Some turf farms also use compost, growing grass in a couple of inches of the material to prevent topsoil loss.