Mother Dirt has expanded its reach into luxury UK retailer Harvey Nichols. The brand will have an interactive pop-up at the store's flagship in Knightsbridge, and products will roll out to Harvey Nichols stores in the UK and Ireland this month.  Mother Dirt is retailer's first probiotic skin care brand.  The Mother Dirt pop-up will be open at the flagship Knightsbridge store until Oct. 31. ...