For this 18 inch high wall the footing should be at least 18 inches wide.
Building a dry stack stone retaining wall.
Lay high quality stones and use a geotextile backing to ensure the wall lasts a long time.
Use a hand or power tamper to level the base.
When putting your wall together mix the stone sizes throughout the wall rather than using only large stones at the bottom and small toward the top.
Even if you don t plan to sit on your wall 3 feet is about as high as i would recommend building any dry stacked wall.
Try to cut the ditch into native soil rather than loose added soil as the former provides a more stable foundation for the wall.
To build a natural dry stone retaining wall prepare the site.
Each layer of a dry stack wall is called a course.
Here are the basic steps involved in building a dry stack stone wall.
Higher walls should be engineered for stability.
The ideal height for a dry stacked retaining wall is 18 to 22 inches so you can sit on it when your gardening chores are done.
Draw the wall to scale and measure the length and height.
For dry stack walls the base should be as wide as the wall is tall.
Excavate to a depth of 6 inches along the entire base of the stone retaining wall using the string marker as a guide.