While there are several types of soil throughout North America, there are a select few that gardeners view as "the best." A good soil will have a balance of good porosity to shed excess water, and enough nutrients to help plants thrive. While not every soil has both of these prized characteristics, a soil that is considered easy to work, and is amendable, is still considered a desirable soil.
Loam is considered the ideal soil type for gardeners. Loam is comprised of 40-percent silt, 40-percent sand and organic matter, and 20-percent clay. The clay lends nutrients to the loam soil, while the sand provides a lighter texture to counteract the heaviness of the clay and improve drainage. The result is a well-balanced soil that is easy to work and nutrient-rich. If you are luck enough to have loam soil in your area, little to no amendments are necessary in order to grow plants. Adding plant fertilizers may enhance plant growth, but this is true of any soil type.
Silt soil has a smooth, almost slippery consistency and is often found in river estuaries where it was carried by the water's flow. Silt's characteristics are very much like a lighter version of clay soils. While silt holds moisture well, its larger particles allow it to drain, unlike clay which often becomes waterlogged. There are enough nutrients present in silt to adequately provide nourishment for most plants, though you may wish to add a plant fertilizer to enhance growth. In areas with silt soil, ensure your gardens are properly graded to shed excess water efficiently. As long as proper drainage is possible, there is no need to amend this soil prior to planting.
This is the lightest of all the soil types, making it the most porous. As the name suggests, sandy soils are mainly comprised of sand particles. This soil type contains no nutrients, but its acidity is hospitable to most any plant type. To successfully grow plants in sandy soil, amend the soil by adding compost to it prior to planting. The compost will provide the nutrients sandy soil lacks and create a nutrient-rich, well-draining soil type. Due to its light texture, sandy soils are the first to warm up to planting temperature in the spring, allowing gardeners with this soil type to get a head start on spring planting.