Is the area deciduous? if it is i would recomend an annual because of the fall of the leaves, the most shade tolerant type of plot i know of is sub-clover this along with any clover, particularly white clover will be a good bet. if leaves are a problem, then a grain (oats, wheat or rye) along with austrian winter peas should do nicely. also try brassicas or rye grass as both of these persist in very unforgiving conditions