Mixed fountain grasses plus pee gee hydrangea, white echinacea ("White Swan"), plus possibly some oak leaf or Annabelle, plus possibly low white carpet rose. Maybe add Icicle White Veronica or similar. Do Russian sage and grasses near steps.
This seemed to me to be cottage garden planting density. Delicate blooms in pink, white, and purple nearly cover the antique urn in this English garden at Wollerton Old Hall. Photo by Clive Nichols Garden Photography.
Liriope muscari 'Isabella' fine leaf compact high wide spreading grass with beautiful pink flowers. Performs well in full sun, drought and recovers well from damage. Used to soften inner courtyard by growing under black metal grill walkways.