|What ground cover would grow in clay soil, full sun, on a steep slope, and look good year around?|
|There are some hardy groundcovers that will fit your site. Ivy will grow there, but sedums or stonecrop will provide seasonal color, as will Ajuga (Carpet Bugle).
There are also low-growing heathers, junipers and cotoneaster that will quickly fillin and blanket the area.
Just be sure to water adequately as your new plants are becoming established, and plan on providing about 1/2" of water per week to them during the first growing season. Since clay erodes easily, mulch the soil around the new plants and water with a gentle spray.