Miniature Dwarf Bearded (MDB)
These are the smallest of the bearded irises, with stems from 2" to a
maximum of 8". These tiny iris are very effective in the rock garden.
They are the first of the bearded iris to bloom in early spring. MDB's
should be planted in clumps for best effect.
Standard Dwarf Bearded (SDB)
These iris bloom after the MDB's but before the Intermediates. They grow
from 8" to 16". These iris have a wide range of colors and patterns
since they were derived from crosses of TB's and MDB's 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's 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's with
TB's they also carry the patterns and colors of both dwarfs and TB's.
They should have at least two branches and should 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's but blooms at
the same time as the TB's. The entire plant (bloom, stalk and foliage)
should be a proportionately smaller version of a TB. Too often BB's 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's are often called
"table iris" because they are well suited for floral arrangements.
Note: the term “Median” is inclusive of classes MDB, SDB, IB, BB and
MTB.
Tall Bearded (TB)
These plants have stalks over 27". 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