For every type of soil, there's a problem to go along with it. Soil issues can stem from many different things: Clay soils, for example, can become compacted like rock when rainfall is low, making it difficult for plants to send down roots or receive water. Sandy and rocky soils may drain too quickly to keep species adequately moist or offer much in the way of plant nutrients.
Compacted soil happens when there's not enough organic matter to break up hard dirt (think of hard clay soil.) This type of issue can also happen when grass is allowed to build up thatch (roots, stems, leaves and other organic matter buildup). When soils compact, it makes it difficult for many plant species to send down roots and can actually repel water and nutrients if it's thick enough. Though it's annoying, remedying compacted soils is fairly straightforward.
Tilling organic matter such as compost into the soil will break it up and prevent settling to the extent of impairing root development. Deeply watering and regularly feeding plants will cause them to send roots deeply into the soil and grow more vigorously. Healthy plants are less likely to suffer from occasional thatch buildup. Aerating lawns with a lawn aerator will remove plugs of soil and thatch: The holes left behind permit air, fertilizer and water to enter the lawn, thus giving grasses a better chance at survival.
Poor Nutrient Content
Soils often suffering from lack of nutrients are sandy, rocky and quick-draining. These soil types are porous and lack the organic fillers that retain moisture and provide food. Plant species that do well in this quick-draining mixture include cacti, sedum and thrift. Natural composts and fertilizers to use can include, but are not limited to, bat guano, goat and rabbit droppings, horse manure, cow manure, chicken droppings, coffee grounds, comfrey leaves, banana peels and other natural nonmeat/dairy kitchen refuse.
Fixing nutrient-poor soils is much like amending those that are compacted. Applying large amounts of compost will not only offer food to plants but help them retain water. Regular fertilizing with natural, safe, organic products (such as worm castings, bat guano and mushroom compost) will not only be valuable to plant health but also offer the added benefit of being safe to use around pets and children.
Poor drainage in an area where peonies, cacti and other plants that require excellent drainage are to be planted can spell disaster for gardeners. Soils that experience bad drainage are usually those high in silt and clay content.
As with compacted soils, adding organic matter in the form of compost, bark, leaves and woodchips will improve drainage. Using underground pipes with holes drilled in the top can help direct water flow away from an area and into a more desirable place. Keep in mind that some areas will be nearly impossible for the average gardener to amend. In situations like this, it's best to choose plants that thrive in said growing conditions. For every type of soil, there are plant species that will grow happily in it.