It isn’t as bad as some alternatives, such as weeds with foxtails in them.

I have ice plant on my back slope and have no rat issues and I’m on a canyon. Perhaps my dogs and the local coyotes keep the critters out.

The only really nice way is to terrace the whole slope, which can get very expensive quickly. You can build a 3′ retaining wall without a permit, so just build a series of 3′ walls with nice flat land between them.

Some materials say you can use a gravel footing instead of concrete. For terracing a large slope, though, I would recommend using a concrete footing anyway. I had one wall on a gravel footing list, and I know a friend who’s wall also went bad on him.

In San Diego, be careful of land that has been declared “environmentally sensitive.” You can’t build structures on that. If you do have “environmentally sensitive” land and it is on a slope that has been cut or filled, you can pull old grading permits, show the city that it is a “manmade” slope and they will lift the sensitive rating.

In Clairemont, a very popular method for building retaining walls is to stack chunks of concrete (from old slabs that have been removed). It isn’t beautiful, but if you make all of the walls with the same method, it has some charm to it in a Clairemont sort of way.