Summary
Moist and wet areas provide the perfect setting for blue flag (Iris versicolor) in the garden. This iris grows 2-3’ tall and during late spring to early summer produces stems displaying several striking 3-4” wide blue flowers, each with a prominent yellow blotch. Its sword-like, upright foliage is an attractive accent to the summer garden. In addition to wet conditions, blue flag grows well in average soil and full to part sun. Blue flag makes an excellent focal point in a small pond or can be used in an area that is too wet for other garden plants. It combines nicely with royal fern (Osmunda regalis), turtlehead (Chelone glabra), cinnamon fern (Osmundastrum cinnamomeum), Virginia meadow-beauty (Rhexia virginica) and common boneset (Eupatorium perfoliatum). Zones 3-9.
The cultivar ‘Purple Flame’ (Photo 4) has purple foliage that emerges from the ground in early spring. As the weather warms, the bold purple leaves start to fade, eventually turning back to tones of green more typical of the straight species. Mt. Cuba Center introduced it in 2020.
More Details
- Plant Type
perennial - Sun/Shade Conditions
full-to-partial-sun - Foliage Character
deciduous - Soil Moisture
average-to-wet - Flowering Period
late-spring-to-early-summer - Soil PH
adaptable - Flower Color
blue, purple - Summer Foliage Color
green - Fall Foliage Color
green - Other Common Names
Northern blue flag, Large blue iris, Harlequin blueflag, - Fruit/Seed Color
black, brown
Additional Information
Missouri Botanical Garden, Lady Bird Johnson Wildflower Center, Flora of North America