There are no selective herbicides for it. In fact there is no real cure, even RU can fail as RU doesn't kill the rhizomes. The only thing that I have heard of that has reportedly "good" results is coving the areas with clear plastic during a hot sunny period (7+ days) and cooking the soil.. Sorry.

Roundup and a whole bunch of other weed killers, including the supposed long term ones are not nearly as nasty as some think. I have a crushed granite driveway parking lot and last summer I put five different kinds of weed/grass killers on it to kill weeds. Not one single one came even close to killing all the weeds, including areas that were repeated ly resprayed. They can be annoying on a lawn when one gets careles and over-spray gives a temporary brown spot, but unless one uses agricultural/commercial grade spray, I believe they are over-rated. The only thing I ever used on the drive-way that lasted a full year was old gasoline that had become to much like varnish. As I wrote in another thread, IF you can get help and have access to a rental store. Rent a sod-cutter and cut the sod off and either haul it away or have them dig a pit deep enough so that a covering of dirt can be put over the stacked sod, even if three fourths are above grade, as it will turn into a dirt mound quite quickly.

What is the difference between crab grass and quack grass? I believe I have both. I think crab grass has thicker leaves than regular grass and grows faster than regular grass. It also tends to grow in clumps. However, with regular mowing, it is not that noticeable. Quack grass, on the other hand, poisons the grass around it so that it leaves bald patches in the lawn. It looks like regular grass on top, but has thin, stalky, brown stems. It's fairly easy to pull, but it always comes back and then some. I find it much harder to deal with than crab grass. Why do you think what Mimi has is crabgrass and not quackgrass, debsflowers and frozen north? Is crab grass more common? As I've posted here before, I'm completely reseeding my front lawn this fall. However, I am now finding quack grass (I think) in the side lawn so I share Mimi's interest in ideas for getting rid of it.

My entire lot is slopes like this, and we have been in the process of trying to find a solution since we bought the house two years ago. I have had the most success with spraying the weeds/grass with round up and letting most of them die off, then covering the slope with a layer of cardboard, then mulch. Surprisingly, I haven't had too much trouble with sliding despite steep angles. Once everything is good and dead (after a time, the cardboard smother anything the roundup didn't kill and help keep new things from rooting), plant ground cover - you'll have to poke through the cardboard to plant, but that's not a big deal.