A retaining wall is basically a wall that is built to hold back the soil behind it. This type of wall is used in many commercial and industrial settings to reduce soil erosion or create a level surface. While these issues might affect individual homeowners, in residential Philadelphia, retaining walls are more commonly used for aesthetic rather than structural reasons.
Retaining Walls in Philadelphia Landscaping
Your existing property may not be exactly what you picture in your head when you think of a perfect yard. In many cases, both the land itself and whatever is growing on it just aren't creating quite the right effect. By utilizing one or more retaining walls, Philadelphia residents can dramatically alter the look of their property by creating tiers or leveling out steep surfaces, and, in some cases, expand the possibilities of what can grow there by regulating the degree of water flow to specific areas of the yard.
Aside from just appearances, there may be physical drawbacks to the lay of your land that inhibit the vision you have picked out for it. Even a slope that is slightly more than gentle might hinder you in bringing your design to life, whether it is a straight and true path to the front door or a level area to put that big trampoline you've always wanted. These sorts of projects can benefit by using a retaining wall, and Philadelphia residents with yards that aren't quite on the level should consider this a viable option.
Philadelphia Retaining Wall Types
Under certain conditions that are not likely for residential properties, retaining walls must be built to hold back extreme amounts of earth for extended periods of time. For a job of that nature, anchoring and other structural reinforcements are a necessity. Most homeowners, on the other hand, can get away with much simpler designs to tier their yard or to make it level. The vast majority of retaining walls built simply for landscaping are, in fact, simple enough to do yourself, as long as you don't mind the labor (which can get pretty intensive).
Once you've found where you want to put it, a retaining wall can be made in a few different ways. Each technique has its own unique look, and no one way is right for every home. Some are constructed by pouring concrete into a mold creating a solid surface with few (if any) seams; others are done using traditional masonry, which has a rustic appearance. Both of these methods are tried and true ways of creating a visually appealing and structurally sound retaining wall, but each requires a specific skill set (and sometimes special equipment) to do well.
A retaining wall can also be made by using a "dry' stone method, which is probably the easiest way to do it. Dry stone walls are constructed without mortar and depend on the friction between the stones and gravity to keep them in place. They can be made using found fieldstones for a rugged look, or formed concrete "stones" (which is concrete poured in a mold to make a series of uniform, stone-like blocks) for an appearance that is more polished. Additionally, concrete stones that interlock can be purchased to make the process even easier.
Prices of Philadelphia Retaining Walls
The cost of building a retaining wall will obviously greatly depend on its length and height. It will also be determined by the method in which it is constructed. If you take the average cost of every retaining wall project nationwide, construction generally takes a week or two and costs about $5,000. (Philadelphia costs seem to be similar to prices throughout the country). Hiring someone to make a masonry wall is more expensive than hiring someone for a poured concrete or dry stone wall. The least expensive option is to do it yourself, but once again, this is not an easy job. DIYs should be prepared for some long hard labor. 
Jon Nunan is a freelance writer who draws on his experience in construction, ranging from landscaping to log home building, for his articles on home improvement.