See the circle around the edge?  It’s not a complete circle, but it’s nearly perfect in shape, and the line is pretty much a constant width.  It’s definitely not a fairy ring; while that would have been cool, fairy rings are not typically found in Sacramento, where the climate is not friendly to them.  Besides, there are not now, nor have there ever been, any mushrooms.  It would have been cool, though.

We had a gardener come and look at our yard today, and I asked him about this.  He suggested that maybe the previous owner had a swimming pool set there (though wouldn’t that have made it a complete circle, full of dead grass, instead of a ring?), or maybe someone, as a gag, sprayed a circle of Round-Up.  He said the grass should recover with regular care, though.

But I’m still entertaining suggestions and theories.  I like that it might be a small scale crop circle, but the possibilities are endless.  Anyone have any ideas?