Answer: I am guessing you are talking about bearded iris? Different types of iris like different conditions, i.e., some iris demand good drainage, some prefer near boggy conditions. I am going to go out on a limb and address bearded. Bearded iris demand well drained soil, preferably of a neutral pH. They like the soil to be pretty high in organic matter (accomplish this by working in lots of compost, leaf mould, or composted cow manure into your planting area). Flowering is at it's best when this iris is in full sun. Bearded iris don't like to be crowded, growth is best when plants are spaced 12-15" apart. One trick I use to cut down on problems with rot and root maggots is when dividing (or moving), dip the roots in a 1 part bleach to 10 parts water solution before replanting. Also, try to plant the roots so the tops are visible. If you think drainage may be a problem, plant the iris in soil mounds.
Q&A Library Searching Tips