Bearded iris are identified by the "beards" on each of the falls of the blossoms. Portions of the following descriptions of the six groups of garden irises are adapted from the American Iris Society website.
There are thousands of photos of irises available on the internet, but which ones grow and thrive in Minnesota? Irises pictured on these group pages are those that Minnesota gardeners have had bloom in their own gardens (at least for a time). All photos are from member gardens, unless otherwise noted. Members are encouraged to send photos to the site administrator so they can be added to these pages, but please follow the submission guidelines.
1. Miniature Dwarf Bearded (MDB) The tiniest of bearded irises, with height of up to 8 inches. The MDBs are the earliest to bloom. They are very effective in rock gardens and planted in drifts. For more information see the Dwarf Iris Society.
2. Standard Dwarf Bearded (SDB) Ranging in height from 8 to 16 inches, the SDBs are some of the most useful garden plants. They bloom early in the season, after the MDBs. There is a wide range of colors available, and they are best grown in clumps.
3. Intermediate Bearded (IB) IBs are from 16 to 27 1/2 inches tall, and they bloom between the SDBs and the TBs. Flowers on the IBs are generally smaller than on the BBs.
4. Border Bearded (BB) These irises are basically small versions of the TBs with the same height range as the IBs, but they bloom at the same time as the TBs.
5. Miniature Tall Bearded (MTB) Height from 16 to 27 1/2 inches, with thin stems and delicate flowers. The blooms are smaller than those of the BBs. They are well suited for arrangements. More information on SDBs, IBs, BBs, and MTBs can be found on the website of the Median Iris Society.
6. Tall Bearded (TB) Stalks are 27 1/2 inches and above, with branching and many buds. TBs are available in a wide range of colors and patterns and exhibit ruffling and lacing more frequently than the other classes. See more about TBs at the Tall Bearded Iris Society site.
It is possible to have bearded irises blooming in our Minnesota gardens for many weeks with the sequence of blooms available to us in these garden groups. In addition, some bearded (and beardless) iris rebloom under certain conditions. Here is interesting and useful information on reblooming iris, written by Jack Worel.