Reblooming Bearded Irises
Introduction

The acceptance of rebloom in bearded irises required heroic persistence by a handful of dedicated breeders working for the trait during the second half of the twentieth century. Any advances in the early years of development were usually dismissed or discouraged. Promising seedlings usually ended up on the compost pile. Flower form and a limited color range made remontants a tough sell in the iris marketplace.

The pioneering efforts of the late Dr. Lloyd Zurbrigg of Durham, NC largely went unnoticed by the general public until a flattering article appeared in a national magazine in the late nineties. Sudden interest in rebloom took the iris world by surprise. Large-scale growers were forced to devote a portion of their annual catalogs to rebloom selections. Thanks to their new public popularity, breeders are now spending more time and resources on future remontant development. New creations can be expected in the coming years.

The mechanism for multiple rebloom in the bearded iris classes is still hard to pinpoint. Theories continue to circulate trying to explain this valuable tendency. Weather seems to play an important role in activating summer and fall flowering. The genetic makeup of these plants result in limited periods of dormancy. Vigorous growth increases the year round availability of mature rhizomes to flower. Summer night time temperatures below sixty degrees F particularly in early August will initiate a second bloom response. Reblooming bearded irises created in the Middle Atlantic Region usually respond to this stimulus. There are exceptions to this rule. The absence of water and nutrients in dry years can stall repeat flowering. Infrequent division of mature clumps can also limit or eliminate the prospects of fall rebloom.

Some popular cultivars touted as rebloomers on the West Coast may not perform in the same manner here in the eastern US. These irises may require additional stimulus to initiate fall flowering. Under the right set of growing conditions, these remontants seem to flower in October and later in the fall. The secret to success is to plant selections bred for your climate or hardiness zone.

Roots & Blooms, LLC through the Joyce Lockatell Memorial Garden worked closely with Dr. Zurbrigg in his later years to grow some of his seedlings to better understand rebloom. Recent results are encouraging. The future remains bright for new flower colors and patterns with outstanding modern flower form.

Check out our current recommended selections for Central VA.

For more information about Bearded Irises please use the links below.

Bearded Iris Care - How to care for the bearded iris.

Bearded Iris Rebloom Summary 2008 - See fall results from our Powhatan, VA location. Also, our current rankings.

Bearded Iris Availability - What we currently have available.