Are you thinking about building a retaining wall? A retaining wall is a structure that is used to hold back the soil, like a slope or hillside, to create a planter or to make more usable yard space. These beautiful barriers also make inviting spots to sit and can increase usable yard space by terracing sloped properties. There are many choices for creating a magnificent retaining wall. Walls used correctly with the right material can add function, comfort and increase the outdoor living space. If you are building a retaining wall or replacing one, consider the following: 1. Retaining walls fall under most city and county ordinance, so get information on the requirements in your area. A couple of phone calls or a visit to the local government can save you tons of money and time. 2. A beautiful retaining wall looks simple and easy, but don’t be fooled. Unless you are doing a small garden wall, lower than 3 feet high, get some help. Invest a few dollars for a local engineering plan and get an experienced contractor to build it. Building a retaining wall is labor intensive and requires some skills. The taller the wall, the more safety conscience you should be. One consideration is to do step-terracing by building two smaller walls versus one large wall.   photo by TERRIGENOUS Landscape Architecture. 3. Do you ever see walls that bulge; have sand or wet spots in the middle of the wall?  Most likely the drainage behind the wall was not addressed correctly. Watching the soil sink behind the wall after a heavy rain is unsettling and problematic. Using proper drainage is a step often skipped in construction. A 4-foot-high wall, 15 feet long could be retaining as much as 20 tons of earth (This Old House). Drainage cloth, gravel and a sock covered corrugated pipe are products I often use when constructing drainage. Don’t forget that incorporating berms and swales into the final design is an easy way to direct surface water away. Walls over 4 feet tall work best with a toe drain to remove incidental water from behind the wall. 4. Is the retaining wall needed for more than 15 years? If so, stay away from railroad ties and landscape timbers in constructing the wall. These materials are less expensive, but longevity is short lived compared to other choices such as rock, concrete, landscape blocks, and brick. 5. According to This Old House blog, if you have your retaining wall built, figure about $15 per square face foot for a timber wall, $20 for an interlocking-block system or poured concrete, and $25 for a natural-stone wall. Preparing a troublesome site—one that includes clay soil or a natural spring, for example—can raise costs substantially. Add an average of 10 percent if you hire a landscape architect or engineer, but shop around; some landscape firms do the design work for free if they do the installation. Retaining walls are a great way to add usable fun space to the yard. Be safe and enjoy your new yard. Planting to Grow, Jeff