Ground Covers Under Spruce Trees

A fairly easy one, I think...
What grows under spruce trees? I know the soil has different qualities... I'm looking for low and medium groundcover.

The type of shade under coniferous evergreens such as spruce, pine, and cedar presents special challenges for herbs. Even herbs that grow dense shade in temperate forests cannot survive the year round shade under evergreens because they need the extra sun they get in early spring before the trees leaf out. Examples are wild ginger and american mandrake.
In addition, there is the effect on soil quality that evergreens have, as you have alluded to.
Ground herbs that are known to grow under coniferous evergreens include: periwinkle (Vinca minor), squaw vine (Mitchella repens), uva ursi (Arctostaphylos uva-ursi) and wintergreen (Gaultheria procumbens). You can also try faster growing herbs such as Faassen's catnip (Nepeta x faassenii) and even herb robert (Geranium robertianum). The latter is actually an annual but it reseeds itself every year forming a dense mat about 12-18 inches high. Herb robert should only be planted where it can be allowed to spread because it can be invasive and troublesome if you have other plants nearby.