Miniature Dwarf Bearded (MDB):
These are the smallest of the bearded irises, with stems from 2" to a maximum of 10" in height. These tiny iris are very effective in the rock garden. They are the first of the bearded iris to bloom in early spring, often in late February in the Pacific Northwest. MDB irises should be planted in clumps for best effect.


Standard Dwarf Bearded (SDB):
These iris bloom after the MDB irises but before the Intermediate Bearded irises. They grow from 8" to 16" tall. These iris have a wide range of colors and patterns since they were derived from crosses of Tall Bearded irises (TB) and MDB irises and carry the colors and patterns of both. They are very useful at the front of the border or in front of taller bearded iris.


Intermediate Bearded (IB):
Intermediates grow from 16" to 27" and have their peak bloom after the SDB irises but before the TB's. These are some of the most useful plants we have for the garden. Because they were created by crossing SDB irises with TB irises they also carry the patterns and colors of both dwarfs and TB's. They will produce at least two branches and have flowers in proportion to their smaller plant size.


Border Bearded (BB):
This group is the same height (16" to 27 ½") as the IB irises but bloom at the same time as the TB irises. The entire plant (bloom, stalk and foliage) will be a proportionately smaller version of a TB. Too often BB irises are introduced that are out of class as to height and flower size.


Miniature Tall Bearded (MTB):
This class has the most strict classification. The height range is 16" to 25 " with a height of 21 " to 22" preferred. The class is distinguished by daintiness and delicacy. The blooms should be small and carried on slender, wiry, flexuous stems. The MTB irises are often called "table iris" because they are quite well suited for floral arrangements.


Note: the term “Median” is inclusive of classes MDB, SDB, IB, BB and MTB.


Tall Bearded (TB):
These irises have flower stalks over 27" in height. They should be well branched and have many buds. This class as well as having a wide range of colors and patterns also displays more often such things as ruffles and lacing.


Aril/Arilbred (AR/AB):
The largest of the Aril iris are native to Israel at the south end of the Dead Sea. They are also found in Iran, Jordan, Turkey and north into Russia. The oncocyclus subspecies have one bloom on 6" to 19" stems, while the regelia subspecies more often has two flowers on 9" to 22" stems. Flowers come in a wide range of colors with veins, dots, spots or signals. Arilbred iris are produced from crosses between bearded and aril iris. They are generally have easier cultivation requirements and are a bit hardier in moist climates. OGB-, OGB, and OGB+ signify whether an Arilbred is one quarter aril, half aril or three quarters aril, respectively.