Topsoil options for your lawn and garden

While there are some generally accepted definitions of topsoil (top 12" of soil taken from some area), gardening soil (topsoil with addition of organic matter), and potting soil (almost no topsoil, screened organic matter, and soil amendements), the actual composition and quality varies wildly across manufacturers, and one should not simply trust the label as topsoil from one manufacturer might be better than potting soil from another manufacturer. In general, when looking at soil from a single manufacturer, potting soil will be higher quality and price than their gardening soil, which will be higher quality and price from their topsoil.

Rather than relying on the name of the soil, follow some simple rules of thumb:- Look at the soil (there is always a slightly torn bag where you can look and feel the soil), and avoid soils with a lot of wood chips or woody debris. While this is technically organic matter, it is actually almost pure carbon which will keep sucking out all the nitrogen from the soil until it is fully decayed.- Read the label - a topsoil from one manufacturer might have more compost and organic matter then potting soil from different manufacturer.- Smell the soil - a strong unpleasant odor usually indicated fecal matter that has not been fully composted. This could introduce unwanted bacteria to your property, and could sometimes introduce too much nitrogen, which is released is the organic matter in the soil gets fully composted.

Compost is a different beast, and should be pure decomposed organic matter which can add life to your lawn or garden. But details matter - what was the original organic matter (i.e. organic cow manure, recycled trash from local trash recycling center, or waste from wastewater treatment facility), and wether the organic matter was fully decomposed (remember, check the smell). If you started your garden or lawn with high quality soil, it likely already had enough decomposed organic matter and there is less need for compost, but if you do choose to add compost to your lawn, or especially to your garden, opt towards a high quality, clean compost that will not add unwanted microbials or chemicals to your property.

If you don't want to think about where the poo that your are putting into your soil is coming from, and whether it has been fully processed, great and clean alternatives are alfalfa or corn distillers' grain (you can put it directly into your garden, put if you are adding it into your lawn, you want to get a product that has been ground into fine particles. Adding molasses will further boost good microbial activity in the soil.