Ruellia humilis (Wild Petunia) Soil-Dry Could be a nice replacement

Could be a nice replacement or substitution for boxwood

Mohlenbrock @ USDA-NRCS PLANTS Database / USDA NRCS

provides that exact habitat

Height: 4'-5'

Amelanchier canadensis is a an absolutely beautiful small tree (or large shrub) with masses of white flowers each spring

Ruellia humilis (Wild Petunia) Soil-Dry Could be a nice replacementRuellia humilis (Wild Petunia) is a short native perennial. This plant is an excellent choice for native landscaping because of its showy flowers and contained shape and nice foliage. It can be installed in many sun and soil conditions. It can aggressively reseed because when ripe it seeds pop sending them flying into adjacent areas including sidewalk cracks and the like. Sun Exposure Prairie Savanna Soil Conditions Mesic, Dry Mesic, Dry Height 1' 2'