One of the most protracted arguments I’ve had began when my buddy Leo goaded me by saying, “Dirt and soil are the same damn thing.” Now, having spent many an early morning listening to my soils professor express outrage at anyone who equated dirt with soil, I felt a moral obligation to fire back the words I’d heard a hundred times: “Dirt is the stuff trapped beneath your fingernails; soil is a miracle of nature that took thousands of years to make... ya dufus.” Yes, the last bit was mine, but my point is I thought I’d won until my friend pulled out a dictionary and pointed to this: “dirt n. earth or garden soil.” What do dictionaries know?!

Therein lies the problem. Soil is the lifeblood of plants, yet we treat it like... well, dirt. Not only do we demand complete servitude from it, we assume
it’ll provide us with wonderful plants year after year. So, in tribute to this overworked and under appreciated stuff that’s erroneously (Yes, Leo,
erroneously!) called dirt, I thought a little soil primer was in order.

Simply put, soil is comprised of four ingredients: minerals, organic matter, water and air. Minerals typically make up the bulk of soils and are one of three types: sand, silt or clay. A soil balanced in these three minerals is called loam, and loam is considered the ideal blend because it holds water and air in the right proportions for plants. Shift the percentages in favour of one mineral, and you can have a sandy loam, a silty loam or a clay loam—all of which can still be good, depending on the climate.

For example, even though loam is considered the
soil paradigm, plants grown in drier regions of the prairies are usually a little better off in clayey loam because it holds more water. In wetter regions, such as those on the West Coast, plants often do better when grown in a sandier loam because of the increased drainage it provides.

The one golden rule for gardeners from coast to coast is to add organic matter to their soils every year. Organic matter is comprised of microscopic and
macroscopic organisms (think decaying and living critters) that provide plant nutrients and “glue”
mineral fractions together into a nice, porous network that aids in the flow of air and water to plants. The thing to remember, however, is that organic matter is con- stantly being consumed as carbon dioxide by soil microorganisms or washed and blown away through water and wind erosion. Simply adding a two-centimetre blanket of compost or well-rotted manure to the soil each year and tilling it in will not only stem the loss of organic matter but also allow it to build up. It’s that easy.

The amounts of the last two soil ingredients, water and air, will be dictated by the mineral and organic matter fractions of your soil. Soils that are loose allow for good air infiltration. As for the amount of available soil water, that will depend entirly on what both Mother Nature and you are prepared to provide.

So if you’re planning on gardening this year, take moment to think before you dig. Give your soil a fraction of the TLC you give your plants, and remember that no matter what people tell you, soil is not a dirty word.

The Canadian soil map shows the different types of soil represented in long bands and pockets—but in your own backyard, you’re just as likely to be dealing with very specific location conditions. (My yard’s soil, for example, is quite different from my neighbour’s.)

Here’s a handy test you can perform right in the garden:

Grab a handful of soil from the garden and add some water. Roll the soil in your palms.
If it rolls into a nice, fat cigar without breaking up, that’s a sign of excellent
soil texture.
If it falls apart, there’s too much sand in the soil and organic matter needs to be added.
If it’s a long, thin pencil, there’s too much clay in the soil. The only feasible way to
improve clay soils are to either replace the soil with high quality loam or to add large amounts of organic matter, whether peat moss, compost or well-rotted manure.

It’s easier to amend the soil before you plant
than to try to fix it after your plants are in place.

Adding organic matter to your garden soil every year is far more important than any fertilizer.