Growing bearded irises
The Rainbow Flower is the most glamorous and well groomed of all flowers. They range from black to white, through yellow, orange, blue, purple, pink to brown and in every combination possible. The only colour they do not come in is red. They are called Bearded Irises because of the caterpillar of hairs that sit on the lower petals, and known as flags because of the three upper petals that (especially in the past) would wave around.
The Bearded iris is split into 6 different categories; Miniature Dwarf Bearded (MDB), Standard Dwarf Bearded (SDB), Intermediate Bearded (IB), Border Bearded (BB), Miniature Tall Bearded (MTB) and Tall Bearded (TB).
Each category represents a different height and flowering period:
MDB - under 20cm (8in); these flower around April and May with small flowers.
SDB - 20cm to 40cm (8in to 16in); these flower during May with small flowers.
IB - 41cm to 70cm(16.5in to 28in); these flower during May and early June with large flowers.
BB - 41cm to 70cm(16.5in to 28in); these flower at the end of May into June with large flowers.
MTB - 41cm to 70cm(16.5in to 28in); these flower at the end of May into June with small flowers.
TB - 70cm to 120cm (28in to 4ft); these flower at the end of May into June with large flowers.
Planting conditions
Bearded irises must be grown in a very well drained spot with as much sun as possible. In hotter climates it is possible to grow them under trees but in the damp, dull climate of the UK they do need full sun. Plant them with the rhizome, or root, just above the soil. This exposes the rhizome to as much sun as possible and allows it to form flowers for the following season.
Make sure that there is not too much competition from surrounding plants and remove any weeds. Once again this allow the rhizome to get the sun.
Fertilising
Don't feed too much. Bearded irises don't like too much nitrogen in the soil; it causes them to rot, as does too much water.
Dividing
Lift and divide your established plants every 3 years or so, from August to late October, before the soil gets cold. If a plant becomes over crowded it will fail to flower.
Diseases
Irises in the UK tend to suffer from two problems
1. Rhizome rot. This is caused by wet conditions and is noticed with the rhizome becomes wet, and very foul smelling. Cut out the affected area and allow the rhizome to dry out. If it is too bad the plant will die out.
2. Leaf spot. Again this is due to wet conditions, but this time the fungus is air borne and thrives in damp environments. The leaf becomes spotted with small, brown dots that will eventually join up and work its way down the leaf. It is more noticeable in the autumn as the plant starts to die back. This does not kill the plant, unless it is very bad, and can be controlled by removing the infected leaves, then sprayed with a fungicide.
National Collection Holders of Bearded Irises
We have been National Plant Collection® nolders of Bearded irises for some years now. Officially the collection contains 513 varieties, but we grow many more. Our iris fields are open to visitors during the blooming season. Please contact us for further details.
BRITISH IRIS SOCIETY
Anyone who really wants to know more about irises should take a look at the British Iris Society.
As British Iris Society Year Book editors, Ric and I are always looking for interesting articles. If you have something to say about irises, please don't hesitate to contact us.