At the most basic level there are three types of soil: sand, loam and clay. Most soils are a combination of the three, in various proportions. Every soil type has qualities and defects.
Sandy soils drain very well, they are easily tilled and provide optimal conditions for the development of root vegetables. They are nutrient poor and dry up easily. A variation of this soil is silt, which is the worst of both worlds: it has the small particle size of clay and the looseness of sand, all the defects and none of the qualities. This soil is practically unworkable unless amended.
Loamy soils, though considered ideal for gardening, warm up quickly and have poor nutrient retention. They are very light weight and perform poorly in containers. On the plus side, they start out very rich in nutrients and are easy to work with.
Clay soils are heavy, they take a long time to warm up, but are nutrient rich and they hold on to them and their water well, if the water had enough time to percolate through them.
The dirt in our back yards is usually a combination of the three basic types, and the addition of peat makes it look dark and buttery and turns it into the classic garden soil that comes in bags at the plant nursery. This is the best soil for gardening, even if it will give you quite a workout to carry it home, it is very heavy. It works well in containers, where it doesn’t dry out quickly, and does wonders for the flower and vegetable beds when mixed into the existing soil. It needs a lot of sand in order to grow root vegetables.
An easy way to figure out what kind of soil you have is to grab a handful and crush it inside your fist: if it crumbles, it is sand, if it bounces back, it’s loam, and if it holds together into a ball, it’s clay.
The second component of the soil type is its acidity. A soil testing kit or a pH meter will quickly tell you what you what kind of soil you have, but you probably already know it by now, judging by the kinds of plants that thrive in your garden.
If you can’t keep azaleas alive, for instance, your soil is probably alkaline, as most clay soils tend to be. Acidic soil is usually found underneath large trees, especially evergreens, and will provide great growing conditions for woodland plants. If you are very determined to cultivate specific plants and the soil doesn’t cooperate, amending it with the limestone will lessen its acidity and iron or aluminum sulfate will raise it, but I always found that working with your garden rather than against it yields better results.
Celebrate your soil type by growing the type of plants it supports and they’ll always look their best.
The third component of the soil is its nutrient content. The primary components, nitrogen, phosphorous and potassium, are found in every fertilizer, organic or otherwise, for the rest of them you can pin point a deficiency with a soil test or by plant behavior and add them to the soil individually, but the best way to enrich the soil is a good measure of compost and/or manure.