Most homeowners have little choice in selecting soils for gardens and ornamental plantings.
More often than not, the original surface soil has been disturbed or is of poor quality. So you must build a soil to suit the plantings you want. Composts and mulches are very important in soil building. Compost is the partially decomposed remains of plant materials. Worked into soil, compost loosens the soil for easier penetration of plant roots, water and air, and increases the soil water-holding capacity.