My house is in an area where the native earth is basically solid clay. This means that wet or dry, you can't dig with a shovel and get crumbling dirt — it always clumps together, unless you break it apart with a shovel or until the weight breaks it apart, which usually results in clumps of at least 5" in diameter. It also weighs a ton because of the water it can hold.
All of our yard is now covered, with the exception of a 4' border around the back of our house. We brought in topsoil for these beds, but the topsoil was never really evened out or tilled into the clay.
Through various weed seasons, settling, and dirt transplanting much of the clay is now at the surface again. I'd finally like to get these garden beds sorted out instead of just killing the weeds throughout the season.
Is there any good way to manually till this kind of clay in with topsoil, or is a machine my only option? I am worried that the narrowness of the garden bed will make using a machine very difficult anyway.