Caring for tall bearded iris
80cm and above are tall beardeds.They are called bearded iris because they have bushy beards on each of the lower petals or falls as they are called.
Falls, standards (upright petals on the top above the beards) and beards come in all of the colours of the rainbow. Striking plants are often plain or self coloured. Others have more than one colour or falls one colour and the upright growing standards another colour or a different shade of the same colour.
Some have patterning or stitching, stripes, white patches or an all over haze of a different colour. This adds to the variety. Some rebloom again during the warmer months. They will need some moisture while flowering and a little general fertilizer and some potash during the summer will extend the blooming period. Potash encourages more blooms to appear. Don't overdo it. Lime can be added in the late autumn.
Start with the basics as for most plants and that means the soil. Soil conditions are terribly important for bearded iris as those with heavy soils must raise the beds and add silt or shingle and some sand around the rhizomes. This adds to drainage and the sand stops spores bouncing up onto the foliage. It is an easy remedy. I pop a small fist sized boulder on newly planted rhizomes, especially as I have a bird problem, birds dig them out. Wind also blows the over. Some folk use bent wire. It helps to anchor them to the ground and encourages root growth. Bearded iris need full to half day sun. Plant iris on a mound about 30cm to 50cm apart. This allows for growth as the rhizomes like to extend along the top of the ground.
They enjoy a drier period in January and February. A good baking does the rhizomes a lot of good but the roots must be covered. Split the fresh young rhizomes off the old dead ones every two or three years. Discard the old ones or burn them. Don't leave them around the iris patch. Pull off any old foliage and keep clear of weeds. Do not use bark mulch around them, use river sand.
Round the year care
February The best time for splitting and replanting. They have made new shoots by this time. I like to use a mix of 1 part to 9 of household janola and water to soak roots at this time before replanting when they have dried off. Cut away any sign of rotting rhizomes.
March and April Superphosphate or osmocote etc. for root development and foliage growth and potash for blooms. Discard rotten rhizomes. Watch for aphids and use super shield if necessary.
May and June Rest time for iris. Tidy away all dead foliage and weeds and discard rotten rhizomes. Spray with lime sulphur in late May. A good time to do your roses as well.
July Spray with copper for leaf diseases and use Tararek as an anti fungicide to kill brown spotting on foliage.
August Spray with Shield or confidor for aphids or any remedy that you prefer. Super Shield would help with fungal disease. Once again check for soft rot, lift and tidy or discard rhizomes affected. Spread more sand if it is a problem.
September and October Weed and spray with copper if needed.
November and December Get the camera out. It is payback time for all your work. Stake iris in very windy places
January Let the iris grow and develop new shoots. Spray for aphids if needed. Copper spray if worried about spotting and rust.