Size the trench so there's enough room for the retaining wall block and at least 8 in. of space behind it. Excavate deep enough to completely bury at least one full course, including space for 6 ...

At my last house, a short retaining wall I had around a patio started to lean out toward the lawn. The wall was but 10 inches tall, for goodness sake, with no soil pressure against it.

Q: We built a retaining wall several years ago and had a landscape contractor, who was a friend of my brothers, help with the project. It was about 18’ long ...