The advice you received was correct, despite the claims made by grass seed companies and their "shade mix" products: Grasses are definitely not going to do well with that little sun exposure. Mazus, Ajuga, and Green-and-Gold (Chrysogonum virginianum) come to mind as alternatives, but there are more options. Moisture will be the biggest concern as many shade groundcovers really cannot thrive if they are dry. There are some though, like barrenwort, that will do fine dry. Also, you need to specify how high you want the groundcover to be -- plants up to 1 ft. high are often considered groundcovers, but some people really prefer something that is only a few inches high. Personally, I really like U.S. native viola walteri var. 'Silver Gem' as a shade groundcover. Uploaded with ImageShack.us Click the link below, fill in your information about exposure, etc. and you will get some more choices. The conditions you list seem to leave you with many good possibilities. Good luck! Here is a link that might be useful: Groundcover Selector

Wandering jew coupled with oxalis (wood sorrel) if you are not worried about the wood sorel spreading. IT does like to spread. I found this pairing because I was inundated with wood sorrel. It would grow most of the winter and early spring when the wandering jew was bit back by the cold . Spring time was lucious with wood sorrel. Just about the time the oxalis got rust and died back to the ground, the wandering jew would be popping up from the ground nice and thick. Their colors looked good together too..

If it is heavy shade, you might be better off planting ferns. There are many very nice native ferns available. Intersperse with viola hederacea. If you get sun at some time in the day, you could try something like pandorea. This is actually a climber, but should be OK trailing along the wall. Otherwise you could try hibbertia, which will be OK in light shade, but will need some sun in order to flower. Don't worry too much about winter shade. So long as you get part sun in spring, you can plant almost any forest species.

I am trying Pigeonberry for the first time this year, to be planted in my dappled shade garden. I've read they can go dormant in the heat of summer if they get too dry but since this is a Texas native, I'm not certain how dry DRY needs to be before this dormancy kicks in! :-) Red berries for the birds, blooms from early spring through fall for the pollinators and butterflies, pretty fall color, height 1 to 2 feet on average. Not certain if the height is too tall for you. There are many discussions about this plant here in the garden forums, if you think you might be interested in taking a look. Just do a search for Pigeonberry or Pigeon Berry. The proper name is Rivina humilis aka Rouge plant. I currently have small seedlings I started from seed and they're growing well. Can't wait to see how they do this season. Best of luck with your new plantings. Mary