Large fieldstones are called boulders. Boulders are rocks big enough to create retaining walls. Individual boulders are also commonly used in a landscape bed to add a feature or accent.
Bouders and Rocks

  • 4” – 8” Border Rocks:  The smallest are 4” to 8” borders stones. These are great to use around a landscape beds to create a natural looking border which separates the grass from the bed.  Scroll down this page further for detailed tips on using boulders in your landscape.
  • 8” – 12” Small Boulders: The next size is the 8” to 12” boulders. These are substantial enough to build small retaining walls. These boulders will not require powered machinery to put into place although they are very heavy. Other tools may be necessary to use for leverage as the largest ones can weigh easily up to 150+ lbs. These are the largest rocks recommended for building walls where powered machinery is not available.
  • 12” – 24” Medium Boulders: The next size is the 12” to 24” boulders. These are the most common boulders used for constructing retaining walls. These rocks should be handled with powered equipment to avoid injury and for ease of placement, considering a 24” rock can weigh as much as 700 lbs. Typically a professional landscaper will use these together with some 24” to 36” boulders and a skid-steer loader to construct a retaining wall.
  • 24” – 36” Large Boulders: The largest size is the 24” to 36” boulders. These are typically used in conjunction with the 12” to 24’ boulders to build medium and large retaining walls.