Competition with Japanese stiltgrass can be challenging. It would be a good idea to plant a mix of native ornamental grasses, perennials, or shrubs so you do not lose the stand to an insect, disease, or cultural/environmental issue. You did not mention if deer are a problem.

Here are some suggestions.
Northern Sea Oats / River Oat, Chasmanthium latifolium
Bottlebrush grass, Elymus hystrix
Tufted hairgrass, Deschampsia cespitosa
White Wood Aster, Aster divaricatus
Woodland Sunflower, Helianthus divaricatus
 Itea virginica, sweetspire, dwarf cultivars (shrub)

Also, here are our webpages on ornamental grasses, native deer resistant plants, and a publication detailing a longer list of MD native plants with their habitat preferences
https://extension.umd.edu/hgic/ornamental-and-native-grasses-landscape
https://extension.umd.edu/hgic/topics/deer-resistant-native-plants-list
 https://www.fws.gov/chesapeakebay/pdf/NativePlantsforWildlifeHabitatandConservationLandscaping.pdf

Marian

Thanks so much for the advice, very helpful.
Grace