Why not river rock? About the only things dogs will not destroy. They use it lot in Colorado for xeriscaping.

Here is a link that might be useful: Propagating Perennials

I don't think that rocks would be very nice for her little grandkids to play on. I need suggestions for something green. Surely you can come up with something attractive; I told her that gardenweb could supply the perfect solution. Otherwise it's going to be AstroTurf!

johnsaunt, there was recently a small thread on the perennials forum about hair cap moss. I'd never heard of it, so I read the post, and I think that I actually have tons of this stuff.

It was here when I bought the house, covering almost a quarter of my yard. It is in poor soil, in areas with rock ledge so I assume the soil is fairly shallow, and gets at least half day shade with morning sun (some areas in deeper, longer shade).

It is absolutely wonderful to walk on in bare feet when it is not dried out, so the kids should love it, and seems to take pretty heavy traffic. Again, I'm not absolutely sure that this is what I have, but it seems to be.

I've never in my life attempted to actually plant a moss, so I'm not sure what is required. I put a link below to some info on hair cap moss, and here are a few links to vendors that I randomly picked off of a google search, so I have no idea as to the vendors' reputations, but just wanted to show that I can this stuff can be purchased.

http://www.mossacres.com/product_haircap_moss.asp

http://www.tripplebrookfarm.com/iplants/Polytrichum.html

I hope this is of some help!
:)
Dee

P.S. Several descriptions say this can get to 12" tall, but mine is only about 2" tall, and on further research I found that there is a range from 2" to 12".

Here is a link that might be useful: hair cap moss

That looks interesting, Dee. Thanks for the links. I'll pass it on to my cousin.
Ginny