Here's a trick to finding a floral designer: Work backwards.
I started by looking for a wholesaler. Mayesh is one of the largest in the country. From there I searched their North American farms, which is how I found Floret Farms, which is based in Washington. I went to FloretFarms.com to discover that the boutique-style farm only grows flowers that are unique, hard to find and bespoke. They're the type of flowers you always see in magazines but never in a florist's shop!