As the name implies, top soil is the uppermost layer of native soil. There is a lot of variation depending on its source, but generally it has few nutrients. Top soil is useful for filling in holes, building up berms, or beneath lawn sod or grass seed. Top soil is not free of weed seeds and it is not sterile. On its own, it is very heavy and compacts easily making it a poor choice for container gardening or seed starting. It can be used in flower and vegetable gardens, but needs to have additional organic matter such as compost or manure mixed in. Sold in bulk and bags.