Hardy geraniums (cranesbill) are a classical pairing and you've pretty much got your choice of colors and sizes. Another good choice is Veronica peduncularis 'Georgia Blue', a low growing evergreen GC with bright blue flowers over a very long season that bronzes up in winter. I also like many of the low growing campanulas, like C. portenschlagiana (Dalmatian bellflower), C. porscharskyana (Serbian bellflower) or C. carpatica 'Blue Clips' or 'White Clips' (Carpatian bellflower). All of these can be planted with or amongst spring flowering bulbs - the bulbs will just grow up through them. In my climate, some of them bloom simultaneously and make a nice early spring show.

You will often see lavender recommended with roses, but that's not a good idea at all. Other than sunlight, it does not share any similar growing requirements and keeping the roses and clematis happy will make for very unhappy lavender and vice versa.

Thankyou gardengal! I was looking at the same ones online, campanulas, sound nice. I was also thinking some sort of annual like million bells. Then I could just mulch right over them in fall. However, what ever one I do get will get some small amount of foot traffic. I have to step in the bed somewhat to prune my roses and clems.

As a grower of over 300 roses. I like to keep my maintenance down, so I only grow groundcovers under my roses that are annuals, or perennials that die down to the ground in the winter. This makes spring cleanup so much easier. But if you're only growing a few roses, then you won't need to follow this advice. I have about 60 climbers and grow clematis on many of them. I don't like to plant groundcovers with deep roots with my clematis, because clematis are heavy drinkers, so most are underplanted with shallow rooted annuals. Those that don't have groundcovers, I just heavily mulch. I have seen "groundcover under Roses" discussed very often on the Rose forum. Maybe they can be of more assistance.

I vote for the campanula too!!! I planted a couple of C. porscharskyana in the spring of 2007 and loved them so much that I got a couple C. carpatica 'White Clips' last fall.

One correction I have to make: Marie Fransiska is supposed to say Franziska Marie clematis. Sorry about that.

Nepeta isn't a low groundcover per se (there are taller and shorter varieties), but is a common underplanting for roses according to my research.

Ajuga is a nice hardy maintenance free groundcover as well. Ajuga will tolerate light foot traffic.

I have campanula blue and white clips....not that impressed but they've only had one growing season thus far...the stems are somewhat woody, I don't imagine this would be the type of plant you'd want to walk over.

Ajuga is probably a better option if you are looking for a low growing groundcover that fills in nicely and is shallow rooted. Pretty flowers too.

Thanks all! I finally decided on Campanula Blue and White Chips, Dianthus Dwarf Sweet Williams, and Myosotis Forget-me-nots for around the roses and clems. They all stay pretty short, and nice color combos I think.

I have 50 old rose bushes and a rust problem. I know to defoliate periodically and to keep air flow at a maximum. What would be an extremely low-growing GC that would prevent erosion without compounding the rust problem?