Plant, Tree & Shrub Library

Ornamental Features

Flag Blue Iris has masses of beautiful blue flag-like flowers with yellow falls at the ends of the stems in mid spring, which are most effective when planted in groupings. The flowers are excellent for cutting. Its sword-like leaves remain green in color throughout the season.

Landscape Attributes

Flag Blue Iris is an herbaceous perennial with tall flower stalks held atop a low mound of foliage. Its medium texture blends into the garden, but can always be balanced by a couple of finer or coarser plants for an effective composition.

This plant will require occasional maintenance and upkeep, and should be cut back in late fall in preparation for winter. Deer don't particularly care for this plant and will usually leave it alone in favor of tastier treats. It has no significant negative characteristics.

Flag Blue Iris is recommended for the following landscape applications;

• Mass Planting
• General Garden Use
• Water Gardens
• Bog Gardens

Planting & Growing

Flag Blue Iris will grow to be about 24 inches tall at maturity extending to 4 feet tall with the flowers, with a spread of 30 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 24 inches apart. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 10 years. As an herbaceous perennial, this plant will usually die back to the crown each winter, and will regrow from the base each spring. Be careful not to disturb the crown in late winter when it may not be readily seen!

This plant does best in full sun to partial shade. It is quite adaptable, prefering to grow in average to wet conditions, and will even tolerate some standing water. It is not particular as to soil type or pH. It is somewhat tolerant of urban pollution. This species is native to parts of North America. It can be propagated by division.