|Iris are an incredibly diverse group of bulbs and rhizomes, encompassing over 200 species and numerous cultivars. They range widely in cultural requirements, some are drought tolerant, while others require a pond to flourish. Flower color and size vary dramatically as well. Foliage is grass-like or sword-like, and flowers are complex, very showy. The three inner segments(known as standards) are petals, the outer ones(known as falls) are sepals. There are three main categories of irises: bearded, beardless and crested. Bearded iris are the most popular and well known, and come in virtually every color. The iris borer is a serious pest, found east of the Rockies in Canada, south to Washington, D.C. west to Iowa. Small piles of "sawdust" near the iris rhizome, is the sign of iris borer. Where winter temperatures remain above 10F, it is absent or rare. It is a larval form of a moth, the main prevention is a good fall garden cleanup of debris where larva can overwinter.
I. laevigata is a Laevigatae beardless iris that bears 2 to 4 blooms that are purple-blue with short standards on unbranched stems and broad leaves to 16 inches long. Most Laevigatae, includes Japanese iris, like moist to wet acidic soil thrives on wet places like ponds. 'Variegata' blooms in a paler purple-blue than its species and has white and green striped leaves.