Grass seed blend for severna park shady sandy yard
See our website on Growing Grass in the Shade and the link below. Soil testing is a good place to start.
You are probably dealing with competition from trees roots as well. Be sure to select a fine fescue grass seed, hard fescue is a good choice. Sow grass seed in early fall. Fertilize once a year in the fall. If not successfull, consider a groundcover instead of grass. http://extension.umd.edu/hgic/shade-lawns
Also, see our publications on Lawn Establishment & Overseeding and Recommended Turfgrass Cultivars