Over forty years after it's introduction, Iceberg is still one of the world's most widely planted roses and with good reason. Plants less than a year old may exhibit hundreds of three inch blossoms on clusters of three to seven buds. Disease resistance is good. Blackspot may make an appearance on occasion, although rarely to the detriment of the plant. Canes are virtually thornless, and the normally dark, shiny, green foliage will lighten somewhat when plants are grouped closely together.
Growth habit is bushy on a nicely formed shrub.
Iceberg makes a fine hedge when plants are spaced more closely than usual, and this brings up an interesting point about the size of this cultivar. I like masses of color, so floribundas are normally planted 18 to 24 inches apart in my garden.