The name implies a big, well, rock garden. But only about 100 feet is rocky at the very south end (easy to walk through this section if you don't like riding technical rocks).
This is a nice and flowy trail that parallels Fallen Leaf Lake Road and offers some great views of Mt. Tallac. It's fast, fun, and flowy as a descent. On the way up (north to south as mapped) it's a pretty mellow climb. It would get four stars if it wasn't right next to the road.
This trail can be used as part of a cool Angora Ridge/Tahoe Mountain Loop: ride this up to the Upper Angora Ridge Trail
and then down Mule Deer Connector
and back up the Angora Ridge Trail and down the Tahoe Mountain trail to Forest Road 12N19