Hi, 

It is probably too sunny for the Azaleas in that location and they are stressed inviting the scale. This looks like Azalea Bark Scale. The link provided gives you management tips if you choose to keep them, but with them being in full sun, they will most likely continue to have problems. 

There are many native flowering shrubs and perennials you could choose depending on the desired traits you are looking for. You can explore different options on the Alliance for the Chesapeake Bay website and put in your garden location parameters. Depending on the planting bed size and assuming there are no deer browsing issues to contend with (which will narrow these options down some), below are some ideas for a mostly-sunny, drier site.

Native shrubs and shrub-sized perennials:

• St. Johnswort (Hypericum densiflorum, Hypericum prolificum) - the latter has better drought tolerance between the two

• Fragrant Sumac (Rhus aromatica, particularly cultivar 'Gro-Low')

• dwarf Eastern Redcedar (Juniperus virginiana) - such as cultivars 'Grey Owl' and 'Grey Guardian'

• New Jersey Tea (Ceanothus americanus)

• Sweetfern (Comptonia peregrina)

• dwarf Black Chokeberry (Aronia melanocarpa) - varieties 'Low Scape Hedger' and 'Low Scape Mound'

• Pasture Rose (Rosa carolina) and Virginia Rose (Rosa virginiana) - the former tends to stay smaller than the latter

• various grasses, like Little Bluestem (Schizachyrium scoparium) and dwarf varieties of Switchgrass (Panicum virgatum)

• False Indigo (Baptisia australis)

• Partridge Pea (Cassia fasciculata, a.k.a. Chamaecrista fasciculata )