Which layer does new soil made in? subsoil soil bedrock topsoil. When does new soil begin to form? when rocks crack to form smaller parts when rocks crack to form bigger parts all of the above. Topsoil is best for... growing plants growing flowers growing trees All of the above. Rocks make up most of this layer of soil. topsoil humus subsoil bedrock. Plants get there nutrients from______________________ minerals and the sun minerals and the soil soil and the sun. Why do we need soil's nutrients? to consume food to produce food to decompose.