I have been trying to establish a large vinca bed, mostly in shade to partial sun, for about three years, and I am now wondering what other groundcovers might work (and look good) interspersed with the vinca.
Why not plant some scattered perennials so you have color throughout the growing season and plant some bulbs in the fall? I am afraid if you plant another groundcover vinca will eventually crowd it out. Plug some of the bearer spots. HD carries flats.
Here is a link that might be useful: Propagating Perennials