Definitions of florist on the Web:

• someone who grows and deals in flowers; "the florist made up an attractive bouquet"
a shop where flowers and ornamental plants are sold
wordnet.princeton.edu/perl/webwn
Floristry, flower arranging, floral arrangement, floral design or floral arts is the art of creating flower arrangements in vases, bowls and baskets, or making bouquets and compositions from cut flowers, foliage, herbs, ornamental grasses and other botanical materials. ...
en.wikipedia.org/wiki/Florist