The Case For Median Iris (Hugh Stout)

  Median iris are basically all bearded iris that aren't "tall". They come in a wide range of colors (much more so than daffodils and tulips!), increase much faster and are usually much tougher than the talls thanks to their ties to species iris pumilla and iris aphylla. This also makes them much more cold hardy growing well even in zone 3. They do require a good winter chill however so if you're in zone 8 or 9 the bloom may be more sporadic depending on your winters. (For more detailed information on the classes I highly recommend the AIS wiki.)

  Miniature Dwarf Bearded Iris (MDB) are the smallest and generally the earliest to bloom. They are up to 8" (20 cm.) tall.

. WEE NOTE, MDB

  Standard Dwarf Bearded Iris are next. They'll bloom around the same time as MDBs but extent a few weeks longer. They are 8" to 16" (21-40 cm.).

QUENCH (SDB)

  Intermediate Bearded Iris come next. They are 16" to 27.5" (41 - 70 cm.). They'll bloom as SDBs are winding down and into the tall bearded season.They are usually created by crossing MDB or SDB with tall beardeds (TB) adding that toughness to the class.

FRIED GREEN TOMATOES (IB)

  Arilbred iris (AB) come in all sizes from small to tall. Generally they bloom about the same time as the intermediates. They usually show a pumilla spot around the beard, one of their defining characteristics. They come from crosses of our usual bearded iris with the true arils or 1/2 arilbreds. While the actual arils are very difficult to grow for most of us, the arilbreds are easier.

PERRY DYER (AB)

  Miniature Tall Bearded iris are the same size as both IB and BB however MTBs are a smaller flower on equally proportioned stalks. Slender with dainty flowers are very appealing.

  Border Bearded iris are again the same size as IB and MTB but more like tall bearded iris, blooming at the same time as them. While there are different roads to creating BBs, generally speaking they are simply shorter hybrids of tall bearded crosses.