Landscape tree shrub advice
You did not mention whether you wanted evergreen or deciduous trees or shrubs and if deer are an issue. Consider a mix of tree species so you do not lose them all to a specific disease or insect problem. You will have to consider the site - sun/shade and the mature height and width of the plants.
Evergreen choices include upright hollies, inkberry, and arborvitae.
Deciduous shrub selections include Clethra alnifolia, Sweet pepperbush; Fothergilla species, and Viburnum species. See our website for planting information as well as publications for a listing of native trees and shrubs and a deer resistant list.
http://extension.umd.edu/hgic/earth-friendly/20-recommended-native-plants-maryland http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG120_NativePlantsof... http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/non_HGIC_FS/FS655.pd...
For more native plant selections see the attached publication "Native Plants for Wildlife Habitat & Conservation Landscaping"
Visit your local nurseries for more information and to see what is available.
Thanks for your response. We would like evergreens to better hide the houses behind us especially during winter months. We have a good fence and a dog so I have not seen deer since we installed fence in November.
Consider the above evergreen choices taking into account mature height and width. The above deciduous shrub selection also offers diversity including bloom and attracting beneficial insects. Create a mix of trees and shrubs so you do not lost the whole stand to a disease or insect pest. Visit nurseries for more ideas.