Bearded Iris are divided into 6 groups defined by their height and bloom period: Miniature Dwarf Bearded (MDB), Standard Dwarf Bearded (SDB), Intermediate Bearded (IB), Miniature Tall Bearded (MTB), Border Bearded (BB), Tall Bearded (TB).
Miniature Dwarf Bearded (MDB)
Up to 20cm in height.
They are the first of the bearded iris to bloom in early spring, late March and April.
Perfect planted in clumps in the rock garden.
Standard Dwarf Bearded (SDB)
Between 21-40cm high.
These irises bloom after the MDB irises, from mid-April to mid-May with a wide range of colours.
They are particularly useful at the front of the border or in front of taller bearded iris.
Intermediate Bearded (IB)
Between 41 – 70cm high.
Their peak bloom period is after the SDB irises, usually from late April to the end of May.
These are some of the most useful plants we have in the garden, with great flower patterns and colours and well-proportioned flowers.
Miniature Tall Bearded (MTB)
At 41-70cm but with a preferred height of 55-70cm.
Flowering from mid-May and through June.
The blooms are small and carried on slender stems.
Often called "table iris" because they are quite well suited for floral arrangements.
Border Bearded (BB)
A proportionately smaller version of the Tall Bearded Iris.
Flowering in May and June.
As the name suggests they are ideal plants for the front or mid garden border, and flower at the same time as the Tall Bearded Iris.
Tall Bearded (TB)
70+cm high, some over 100cm. Which means in an exposed site they may need staking.
The most recognised iris and is typically what most people think of when irises are mentioned.
A vigorous hybrid will be well branched and have many buds. This class has a wide range of colours and patterns and generally displays special features such as ruffles or lacing. The Space Age Bearded Iris is distinguished by a horn, flounce, or spoon like protrusion from the end of the beards.