Today Martha tours the iris gardens at Wave Hill, a public garden in Bronx, New York, with the garden's director, Marco Polo Stufano. Marco prefers smaller, old-fashioned bearded iris varieties, specifically those hybridized in nineteenth-century France, which retain a classic fleur-de-lis shape -- like 'Honorable,' a golden variety. He likes light, delicate colors such as peach and bisque, as well as jewel-like violets and blues.
When a clump of bearded irises becomes too large, you can dig it up, divide it, and replant it. It's best to do this after the plants have finished blooming; mid- to late July is the ideal time. Dig up each rhizome you wish to transplant, and cut back the foliage approximately two-thirds of the way. Cut the rhizomes apart, removing any shrunken or soft parts, and replant so that they are partially exposed at the surface of the soil. Marco recommends alternating the directions in which adjoining rhizomes point -- this creates a stronger, more cohesive clump.
Learn more about Wave Hill.