Dear James: I’m planning a veggie garden on my sloping lot so I need a retaining wall. I have used timbers before, but blocks might hold up better. Which method do you prefer? -- Steve W. Dear Steve: ...

Q. Can you tell me how to build a retaining wall? Are retaining wall blocks a good choice? What critical things do I need to know so that I don't have a collapse or other failure in the years to come?

Retaining walls are a necessity if you have a sloped yard or live in a flood-prone area, but it's necessary to find a design that's actually functional.