You have two options for building a retaining wall with concrete. If you're set on getting the job done yourself without professional assistance, using concrete blocks is the way to go.

Q: I want to build a retaining wall that’s going to look great for years. 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 ...

but in the backyard I used concrete block to build a magical serpentine retaining wall that looks as good today as the day I built it decades ago. Here's the truth. You can build a poured concrete ...