hi, HERE are not my experiences, but have a look...
An idea of mine
include grit) make a mix of Foxtail lily (Eremrus) Allium sphaerocephalon, some types of Heleniums, papaver somniferum, poppies, Achillea ‘Flowerburst Red’, ornamental grasses, Verbena, White Verbasum, Echinacea...Greetings, ThaiGer.